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Cactaceae

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Summary of Family Cactaceae

Cactaceae - Cactus Family
Greek: kaktos = a prickly plant (Spanish artichoke) from Sicily. Linnaeus (1737)

Saguaro

The large family Cactaceae is one of the most distinctive familes of dicotyledenous flowering succulent plants, with around 90 genera and 2500 species, ranging in size from less than half an inch to tens of feet in height and exlusively native to the American continent including the West Indies. The solitary exception to this New World distribution is that of the epiphyte Rhipsalis baccifera which is distributed in Africa, Madagascar and Ceylon as well as in South America, Mesoamerica and the Caribbean. Cacti generally have 22 chromosomes but African variants of Rhipsalis baccifera are tetraploid.
 
Morphology: Most species of Cactaceae are spiny stem succulents, although there are a few woody shrubs (Pereskia) and more or less succulent epiphytes. Some species have tuberous roots or a fleshy taproot. Many cacti have ribbed bodies that allows easy expansion in response to water uptake after brief showers of rain and contraction in times of extended drought. Water loss is reduced by a waxy epidermis. 
All Cactaceae have distinctive modified buds that have evolved into specialised areoles from which grow multiple spines and glochids (right). These should be distinguished from solitary spines or thorns on other plants e.g. spiny Euphorbias, that sometimes branch above the plant body. In some cactus species, spination is minimal, or occurs only during some phases of the succulent plant's life or vestigal spines are present as hairs. Leaves where present are alternate, but usually reduced or absent. Fruits are generally berries with multiple seeds, which may be surrounded by juicy flesh or by a more or less dry membrane and may have external areoles with spines or glochids.
 
Biochemistry: CAM metabolism allows carbon-dioxide to be taken up during cool nights and stored as malic acid for use in photosynthesis during hot, sunny days, greatly reducing water loss during transpiration. Betalain pigments are present and characteristic of the family Cactaceae and of the Order Caryophyllales in which they are included, as is absence of anthocyanin pigments found in many other families of flowering plants. Betalains and anthocyanins never occur in the same plant. Betalains are responsible for the red or violet colouration of some cacti when stressed. Ferulic acid in the cell walls of Cactaceae is also a common characteristic. Hylocereus megalanthus - Yellow Pitahaya
 
Uses: Several species of cacti are cultivated for their juicy fruit (e.g. Opuntia ficus-indica, Selenicereus sp., Hylocereus sp.) orfruit is collected from wild plants. Through introduction, Cactaceae and especially Opuntia are found throughout the tropics. In some places cacti have become invasive weeds. 
Many species of cacti are cultivated as ornamental house plants or for dry landscaping and they are grown from seed in vast numbers. Some species e.g. Echinocactus grusonii are far more common in cultivation than in their habitat, much of which was destroyed by construction of a reservoir. All species of cacti are protected as CITES 1 or CITES 2 plants, which presents a barrier to free trade even for nursery grown cacti and artificial hybrids with no natural distribution.
 
Cactus taxonomy appears to follow a record of their assumed evolutionary history. Various authors have estimated that the Cactaceae evolved as recently as in the last 10,000 years or as long ago as 20 - 30 million years. However, as cacti are not well-represented in the fossil record, the logical taxonomic sequence is based mainly on morphology. Recent DNA studies support the general groupings, but suggest some taxonomic rearrangements of species. This family contains numerous genera which seem to be constantly under revision.

spine cluster
 
spine cluster
 
spine cluster
Above: examples of
cactus spine clusters



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Summary of Cactaceae

go to top  Subfamily Pereskioideae   (leafy cacti)
The 20 species of succulent plants in this subfamily are shrubs and trees with persistent flat leaves, areoles with spine clusters and no glochids. These plants are thought to be low down in the evolutionary tree of the Cactaceae. The two mat-forming species in Maihuenia with persistent rounded succulent leaves are sometimes separated into Subfamily Maihuenioideae.
 
All species in this subfamily are native to central and South America.

Maihuenia  (Philippi ex F.A.C.Weber) K. Schumann 1898
Name: Latinised form of maihuén, Chilean common name for these cacti 
The genus Maihuenia includes two species of dwarf mat-forming cacti as the only members of Subfamily Maihuenioideae. These succulent plants consist of short segmented cylindrical stems with small persistent rounded succulent leaves and typically 3 white spines per areole. Flowers in shades of yellow are produced near the ends of the stems and are followed by club-shaped fruits.
 
Native to elevations from sea level to up to 8000 ft in the Andes Montains of Argentina and Chile. Maihuenia experience frost in their habitat and tend to be cold-wet hardy in cultivation, especially M. poeppigii.

Maihuenia patagonica - RBG Kew

Maihuenia patagonica  (Philippi) Britton & Rose 1919
Name: = of Patagonia, native region 

 
Photographed in the Alpine House at RBG Kew. Said to be the least hardy of the two species, so needs to be kept under cover.

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Maihuenia poeppigii - RBG Kew

Maihuenia poeppigii  (Otto ex Pfeiffer) F.A.C. Weber 1898
Named for: Eduard Pöppig, 19th century German naturalist and explorer 

 
Photographed growing outdoors at RBG Kew. This is the most hardy of the two species and is the only cactus that consistently survives the English Winter outside in my own garden, potted up in almost pure granite chippings to ensure free drainage.

go to top  Pereskia  Miller 1754
Named for: Nicolas-Claude Fabri de Peiresc, 16th century French astronomer, antiquarian & savant 
The genus Pereskia includes 17 species of tropical woody shrubs, climbers or tree-like cacti with thin stems and substantial, persistent non-succulent green leaves. A characteristic feature in common with other cacti are the clusters of spines originating from areoles. Roots may be thickened or even tuberous. Flowers are single and resemble those of a wild rose. It is thought that the primitive features of the genus Pereskia resemble those of a common ancestor to all cacti.
 
Native to a range from Brazil to Mexico including the West Indies. Pereskia is often used to make thorny hedges. Pereskia aculeata has edible fruit (Barbados gooseberry) but may be considered invasive in some places.

Pereskia grandifolia - RBG Kew
Pereskia weberiana - RBG Kew

Pereskia grandifolia  Haworth 1821 (Rose Cactus) Syn. Pereskia grandiflora Hort. ex Pfeiffer 1837
Name: Latin grandis = large + folius = leaves or + florus = flowers 
This cactus grows as a non-succulent tree or woody shrub with a grey-brown trunk up to 10 ft tall. The woody, branching stems have areoles bearing clusters of spines and brownish tomentum but also ovate, glossy, deciduous leaves on short petioles. Flowers resembling those of wild roses in shades of pink are freely produced at the stem ends.
 
Native to dry tropical forests of North-Eastern Brazil. Pereskia grandiflora is grown for its showy flowers and also features in traditional medicine to reduce swelling and inflammation and as an anti-cancer remedy.
Photographed at RBG Kew.
 
 
 
Pereskia weberiana  K. Schumann 1898
Named for: Frédéric Albert Constantin Weber (1830 - 1903), French botanist 
A shrubby non-succulent cactus with areoles bearing both spine clusters and glossy ovate leaves.
 
Native to dry forests of the Andean valleys in Bolivia, at altitudes up to 6000 ft.
Photographed at RBG Kew.

go to top  Subfamily Opuntioideae
This sub-family includes over 300 species of cacti with the common characteristic of irritating barbed hairs (glochids) as well as ordinary spines. The seeds are hardened with a stone-like aril. Leaves where present are vestigial and short lived. Members of this subfamily range in size from mat-forming plants to shrubs and trees.
 
Native to a very wide range from central Canada to Patagonia in South America and naturalised in many warm climates where they may be regarded as invasive.

Brasiliopuntia brasiliensis

Brasiliopuntia  (Willdenow) A.Berger 1926
Name: Opuntia from Brazil 
A monotypic genus for the South-American succulent tree-like cactus Brasiliopuntia brasiliensis.

Brasiliopuntia brasiliensis Brasiliopuntia brasiliensis trunk Brasiliopuntia brasiliensis

Brasiliopuntia brasiliensis  (Willdenow) A.Berger 1926
A stout trunk growing up to 60 ft tall and patterned with areoles, supports rounded branching stems bearing flattened dark green cladodes. Areoles are furnished with glochids and 0 - 3 spines. The flowers are golden yellow and are followed by rounded spiny fruit containing up to 5 large seeds.
 
Native to Brazil, Paraguay, Eastern Bolivia, Peru and Northern Argentina and naturalised in other countries with tropical climates. The pulp inside the fruit is edible.
Photo: RBG Kew.

Cylindropuntia  (Engelmann) Knuth 1754 (Cholla)
Name: = cylindrical Opuntia referring to the stems 
The 35 species of cacti in Cylindropuntia were formerly included in Opuntia but were separated on the basis of cylindrical stem segents and papery sheaths on their barbed spines. Cylindropuntia species range from small sub-shrubs to large trees.
 
Chollas are native to the South-Western USA, Northern Mexico and the West Indies. Large stands of genetically homogenous chollas occur in some places, where plants propagate vegetatively from dehiscent stem segments.

Cylindropuntia bigelovii

Cylindropuntia bigelovii  (Engelmann) F.M. Knuth 1935 (Teddy Bear Cholla, Jumping Cholla)
Syn. Opuntia bigelovii  Engelmann 1856
Named for: John Milton Bigelow (1804 - 1878) American surgeon & botanist 

 
Photo: A forest of Cylindropuntia bigelovii. Cactus garden, Joshua Tree Park, California.

Cylindropuntia whipplei

Cylindropuntia whipplei  (Engelmann & J.M.Bigelow) F.M. Knuth 1935 (Whipple's Cholla)
Syn. Opuntia whipplei  Engelmann & J. M. Bigelow 1856
Named for: Amiel Weeks Whipple (1818 - 1863) U.S. Army surveyor & botanist 
This cactus makes a sturdy 4 - 5 ft spiny shrub with many cylindrical branches covered in oval tuberculate projections. Areoles produce 7 to 14 spines with one long 2 in spine in each group. Green flowers are produced at the ends of the branches in the Spring, followed by cylindrical yellowish green fruits with tubercles but no spines.
 
Native to Arizona, Colorado, New Mexico and Utah. Grows in impenetrable thickets.
Photo: seedling at RBG Kew.

go to top  Maihueniopsis  Spegazzini 1925
Name: Maihuenia + Greek opsis = view, referring to resemblance to Maihuenia 
The genus Maihueniopsis contains 18 - 19 species of cactus, unrelated to Maihuenia. Several species have tuberous roots or taproots. They form low cushions of segmented rounded stems with vestigial leaves that are soon lost. The spination varies from long and lethally sharp to tiny spines held tightly against the plant body. The flowers are mostly shades of yellow, but also red and white.
 
Native to a wide range across Peru, Chile, Argentina and Bolivia, often at high elevations of 13,000 ft above sea level where frost and snow are experienced together with strong light and ultraviolet.
 
The genus Puna has been merged into Maihueniopsis.

Maihueniopsis bolivianum - Holly Gate Cactus Nursery reference collection

Maihueniopsis bolivianum  (Salm-Dyck) R. Kiesling 1984
Syn. Cumulopuntia boliviana subs. dactylifera  (Vaupel) D.R.Hunt 2002
Syn. Opuntia dactylifera  Vaupel 1913
Syn.
This plant forms dense cushions of segmented ovoid stems with areoles producing 0 - 7 spines. Flowers are yellow followed by spineless ovoid green fruits.
 
Native to Bolivia and Peru at high altitudes around 12,000 ft above sea level. In cultivation this species likes cool growing conditions.
Photo: Holly Gate Cactus Nursery reference collection.

Maihueniopsis darwinii

Maihueniopsis darwinii  (Henslow) F. Ritter 1980
Opuntia darwinii  Henslow 1837
Named for: Charles Darwin (1809 - 1882) author of "On the Origin of Species" 
This mat-forming cactus has olive-green cladodes with large areoles bearing stiff, lethally-sharp spines with a raised central rib and flattened margins. Flowers are orange-yellow followed by fleshy fruit of similar appearance to the cladodes. Roots are tuberous and sensitive to over-watering.
 
Native to Argentina and Chile. Tolerates light frost and snow in its habitat.
Photo: RBG Kew

Maihueniopsis minuta

Maihueniopsis minuta  (Backeberg) R. Kiesling 1984
Tephrocactus mandragora  Backeberg 1953
Name: Latin minuta = tiny 
This mat-forming cactus has small, branching, ovoid to conical stem segments up to an inch long. Areoles are sunk into the stem and produce glochids and a few spines recurved against the plant body, or spines may be absent. The relatively large flowers are yellow and followed by fleshy fruits.
 
Native to a limited range in Northern Argentina. In its habitat, the plant is often partially buried in the ground,
Photo: Holly Gate Cactus Nursery reference collection

Maihueniopsis nigrispina

Maihueniopsis nigrispina (Schumann) R. Kiesling 1984
Syn. Tephrocactus nigrispinus (K. Schumann) Backeberg 1935
Syn. Opuntia nigrispinus  K Schumann 1898
Name: Latin nigrispina = with black spines 
This low, shrubby cactus has branching ovoid to cylindrical purplish-green stem segments, with wooly areoles bearing 3 - 5 long spines on newer growth. The black spines fade to gray as the cladode matures. Flowers are red.
 
Native to Argentina and Bolivia, growing at altitudes of up to 12,500 ft above sea level.

go to top  Opuntia  (Linnaeus) P. Miller 1754 (Prickly Pear, Nopales [pads], Tuna [fruit])
Named for: Opus "a town of Locris in Greece". Theophrastus (371-287 BC) mentioned an edible plant growing there that was propagated by leaf cuttings. However, this could not have been an Opuntia as the genus originates from the Americas, unknown in that era. 
The genus Opuntia is a large group of cacti with flattened paddle-shaped stem segments (cladodes) furnished with two sorts of spines: large fixed spines and small, hairlike spines (glochids) that easily detach from the plant and penetrate the skin causing irritation.
 
Native to a wide range of the Americas from British Columbia and Canada to Patagonia, South America, the West Indies and the Galapagos Islands. Opuntias have been introduced to many countries with mild climates and are considered invasive in some.

Opuntia basilaris - Death Valley California

Opuntia basilaris  Engelmann & J.M. Bigelow, 1857 (Beavertail Cactus)
Name: Latin basilis = basal + aris = 'from the base' 
This is a low-growing (2 ft) cactus with gray-green to purplish pads that can wrinkle in drought. The areoles have white or brown wool and brown glochids with occasional spines on new pads. Flowers are bright pink.
 
Native to Arizona, California and Nevada and into North-Western Mexico, growing at up to 3000 ft above sea level.
Photo: Death Valley California.

Opuntia erinacea var. hystricina

Opuntia erinacea var. hystricina  (Engelmann & J.M. Bigelow) L.D. Benson 1940

 
Photo: near Salt Flats, Texas.

Opuntia engelmannii

Opuntia engelmannii  Salm-Dyck ex Engelmann 1850

 
Photo: near Marathon, Texas.

Opuntia lasiacantha Opuntia lasiacantha

Opuntia lasiacantha  Pfeiffer 1837 (Nopal de Cerro)
Name: Latin lasiacantha = wooly, prickly 
This shrubby Opuntia has eliptical stem sections with areoles furnished with glochids and 1 - 3 small spines. Flowers are yellow to orange followed by reddish, spiny, conical, edible fruit.
 
Widely distributed in the Mexican states of Aguascalientes, Chiapas, Guanajuato, Guerrero, Hidalgo, Jalisco, México Distrito Federal, México State, Michoacán, Nuevo León, Oaxaca, Puebla, Querétaro, San Luis Potosí, Tamaulipas, Tlaxcala and Zacatecas, where it is used as food for animals and people.

Opuntia microdasys

Opuntia microdasys  (Lehmann) Pfeiffer 1837 (Bunny Ears Cactus)
Name: Greek mikros = small + dasus = hairy 
This shrubby cactus grows up to 2 ft tall with stems formed from flattened pads joined end to end. The pads have dense tufts of white or yellow glochids but no spines. These glochids are barbed and detatch into one's skin with the slightest touch, causing irritation until removed. Flowers are yellow.
 
Native to central and Northern Mexico. Despite the irritating glochids, this species is common in cultivation and there are numerous selected forms.
Opuntia rufida from Northen Mexico into Texas, is very similar but has rusty-brown glochids.

Opuntia quitensis Opuntia quitensis

Opuntia quitensis  F.A.C. Weber 1898 (Red Buttons Opuntia)
Syn. Opuntia johnsonii  Hort.
Named for: Quito, capital city of Ecuador 
This shrubby cactus grows to 5 ft tall with both prostrate and upright branches. Areoles produce glochids, a few weak or strong gray spines or no spines and on new growth, stubby vestigial leaves which are soon lost. The orange flowers are dioecious, usually one at the end of each stem. Stamens in the female flowers do not produce pollen.
 
Native to Ecuador and Peru growing at low elevations in valleys and plains.

go to top  Pterocactus  Schumann 1897
Name: Greek pteron = wing, referring to the winged seeds. 
The genus Pterocactus includes 9 species with spheroidal to elongated stem segments bearing areoles with glochids but few or minimal spines except in a few species. A single flower is produced from the end of new stems, followed by dry dehiscent fruit containing broad, papery winged seeds. Roots are tuberous and allow the plant to survive loss of its stems during Winter.
 
Native to the Patagonia region of Argentina.

Pterocactus tuberosus
Pterocactus tuberosus

Pterocactus tuberosus  (Pfeiffer) Britton & Rose 1919
Name: Latin tuber = truffle, referring to the thick roots. 
Syn. Pterocactus kuntzei  Schumann 1897
Named for: Dr. Carl Ernst Otto Kuntze (1843 - 1907) German botanist. 
This geophyte develops a huge tuber supporting thin, cylindrical, brownish-purple stems that break off easily, especially during Winter. The dehiscent stems blow in the wind and may root to form a new plant. The tuber produces new stems in the Spring. Pale yellow flowers are produced at the ends of new stems.
 
Native to Northern Argentina and Patagonia, growing in sandy soils with most of the tuber buried. In cultivation, the mature tuber may be raised above the soil for display but will not then grow any larger. As with many tuberous plants, this cactus is quite sensitive to overwatering and should be kept dry during the Winter.

go to top  Quiabentia  Britton & Rose 1923
Name: from Quiabento a Brazillian native name for the plant. 
The genus Quiabentia includes two species of tree-like cactus with a spiny trunk growing up to 50ft tall, branching to form a leafy crown above the reach of herbivores. Quiabentia is related to Pereskiopsis and has glochids in its areoles. The persistent, flattened fleshy leaves are unique to this genus of Opuntiads. Pink to red flowers with spiny floral tubes arise from the stem tips. Flowers are followed by rounded fleshy edible fruit with large rounded seeds.
 
Quiabentia verticillata is native to Argentina, Bolivia, and Paraguay. Quiabentia zehntneri is native to tropical dry forests of Bahia, Brazil. Uncommon in cultivation.

Quiabentia verticillata
Photo: growing at RBG Kew

Quiabentia verticillata  (Vaupel) Borg 1937
Syn. Pereskia verticillata Vaupel 1923
Name: Latin verticillatus = whorled, referring to branches arranged in whorls. 
This tree-like cactus grows up to 50ft tall with spiny trunk and stems furnished with large, flattened oval to lanceolate succulent leaves. Flowers are pink to red followed by rounded fruit containing large, oblong seeds with a white aril.
 
Native to Argentina, Bolivia and Paraguay.

go to top  Tephrocactus  
Name: Greek tephra = ash, referring to the colour of the plant bodies 
The genus Tephrocactus includes 5 species of small Opuntiads, with many synonyms. The stems grow in distinctive rounded segments bearing areoles whose glochids are sunk into them and spines which may be long and sharp or papery or more or less absent. Flowers are usually white to pink, or yellow. Tephrocactus rossianus has red flowers.
 
Native to high elevations in the Argentinan Andes where they experience freezing conditions.

Tephrocactus articulatus var. strobiliformis

Tephrocactus articulatus  (Pfeiffer) Backeberg 1953
Syn. Tephrocactus articulatus var. strobiliformis  A. Berger
Syn. Opuntia strobiliformis  A. Berger 1929
The gray-green plant body is essentially spineless. Flowers are white.
 
Native to Western Argentina.

Tephrocactus articulatus var. papyracanthus
Photo: RBG Kew
Tephrocactus articulatus var. papyracanthus
Photo: Farmer Matt 2015

Tephrocactus articulatus var. papyracanthus  (Philippi) Backeberg 1953
A form of T. articulatus with a well-jointed grey-green body offset by white papery spines with glochids at their base.
 
Native to Argentina.

Tephrocactus weberii Tephrocactus weberii

Tephrocactus weberii  (Spegazzini) Backeberg 1936
Named for: Professor Georg Heinrich Weber (1752 - 1828) German doctor and botanist at the University of Kiel. 
This small shrubby cactus has branching, spiny cylindrical stems that form large cushions up to 8 in in height. Stem segments detach easily. The areoles have glochids and 3 - 10 long, flexible white to brown or black spines. Flowers are lemon to orange.
 
Native to central and Northern Argentina.

go to top  Tunilla  Hunt & Iliff 2000 (Airampo)
Syn. Airampoa  Frič 1929
Name: Tunilla = small tuna, a common Spanish word for Opuntia pads. 
The genus Tunilla includes 9 species of low-growing, mat-forming cacti with flat, jointed cladodes or rounded stem segments. The areoles produce both glochids and needle-like spines. Flowers are yellow to red. Fruits are dehiscent with a single slit, containing many kidney-shaped seeds and red pulp compacted together.
 
Native to Argentina, Bolivia, Chile, and Peru. Uncommon in cultivation.

Tunilla corrugata

Tunilla corrugata  (Salm-Dyck) D.R. Hunt & J. Iliff
Syn. Airampoa corrugata  Frič 1929, Opuntia corrugata  Salm-Dyck 1834
A mat-forming cactus with ovate, flattened segments to the jointed stems. Flowers are reddish with a green stigma.
 
Native to North-Western Argentina.

Opuntia sp.

Opuntia sp.

 
Labelled as O. microsphaericus but that doesn't seem to be a valid name.
Might be a Tunilla sp.
Photo: Holly Gate Cactus Nursery reference collection.


 

go to top  Subfamily: Cactoideae
This is the largest and most diverse subfamily within the Cactaceae, including over a thousand species. This group of plants covers a wide range of forms and lifestyles, ranging in size from less than half an inch to trees over 60ft tall. Most but not all cacti have spines but glochids are never present and leaves are absent or vestigial e.g. cotyledons. Instead of leaves, stems are photosynthetic. Most flower colours are seen with the exception of blue. Flowers are followed by berries which may be fleshy or dry and contain multiple small seeds.
 
All species of cacti are native to the Americas with the exception of a single species (Rhipsalis baccifera) which is also found in India, Ceylon and Africa.

Ariocarpus fissuratus

Ariocarpus  Scheidweiler 1838 (Living Rocks)
Name: Greek aria = an oak type and carpos = fruit 
The genus Ariocarpus includes 8 species of cacti whose spines have mostly degenerated into tufts of wool. These plants grow flush with the ground and have thick tap roots which require very well-drained conditions. The plant consists of a rosette of spineless, triangular tubercles and in mature plants a wooly apex. The succulent tubercles are protected from herbivores by their content of bitter alkaloids e.g. Hordenine.
 
Native to limestone mountains of South Texas into central Mexico. The single species in Texas (A. fissuratus) is not uncommon within its range, but well camoflagued among rocks. However, the shocking pink flowers produced in the Autumn betray the positions and numbers of plants. In cultivation Ariocarpus are very slow growing and require careful watering or the tap root will rot. Some people like to add ground limestone to their potting mixture, which must be very free-draining. Grafting is commonly used to increase the growth rate, but produces bloated plants.

Ariocarpus fissuratus Ariocarpus fissuratus

Ariocarpus fissuratus  (Engelmann) K. K. Schumann 1894 (Living Rock Cactus)

 
Native to Northern Mexico and Texas.
Photo: Big Bend National Park, Texas.

Ariocarpus retusus

Ariocarpus retusus  Scheidweiler 1838
Name: Latin retusus = blunt tip 
This somewhat variable plant is the type species for the genus. The rosette of spineless tubercles is supported by a subterranean tuberous body which requires excellent drainage.
 
Native to the high Chihuahuan desert in the Mexican states of Coahuila, Nuevo León, San Luis Potosi, Tamaulipas, and Zacatecas, growing on limestone and gypsum.

Ariocarpus scapharostrus

Ariocarpus scaphirostris  F. Boedeker 1930
Syn. Ariocarpus scapharostrus  Boedecker 1930
Name: Latin scaphe = peak + rostrum = face 
The tubercles of the mature plant are spineless, but seedlings have spines.
 
Native to the Mexican state of state of Nuevo León.

go to top  Astrophytum   Lemaire 1839
Name: Greek astron = star + phyton = plant 
Astrophytum is a small genus of six species of North American cacti, within which is a remarkable diversity of form. The cactus bodies are globular to short columns with or without spines. The body plan of Astrophytum is star-shaped with 5 - 8 ribs, which may be deeply incised or minimally delineated by a line of areoles. The recently-discovered, distinctive A. caput-medusae has sprawling stems arising from a caudex and is sometimes regarded as a member of the monotypic genus Digitostigma. The surface of all species generally has white patches of flocking but this may be absent or washed away by rain.
 
Astrophytum are native to Southern Texas and Mexico.
The variable symmetry of form and white markings of these plants has appealed to collectors, especially in Japan where many extreme examples have been bred.

Astrophytum myriostigma

Astrophytum myriostigma  Lemaire 1839 (Turk's Head Cactus)
Name: Greek myrios = innumerable + stigma = stain (many-dotted) 
The three to seven, usually five-ribbed solitary plant body is covered with thousands of tiny dots of white trichomes to a variable extent. There are no spines. Yellowish, sweetly-scented flowers with many petals are produced at the apex of the plant and are followed by a large (1 inch) red fruit.
 
Native to the Mexican states of Coahuila, Durango, Nuevo León, San Luis Potosí and Tamaulipas. The plant should be watered from below to preserve the white flocking. Some all-green horticultural selections have no trichomes.
Photo: Benno Stander 2014, of a cultivated plant in South Africa.

Astrophytum myriostigma quadricostatum

Astrophytum myriostigma quadricostatum  M. Mittler 1841
A nursery-selected form with four ribs instead of the more usual five ribs. Such plants also occur in the wild population. Flowers are pale yellow. Further selections have led to all-green plants without white trichomes and several named cultivars with distinctive patterns of white trichomes.

Astrophytum ornatum Astrophytum ornatum

Astrophytum ornatum  (De Candolle) Weber ex Britton & Rose 1922 (Bishop's Cap)
Name: Latin ornatus = decorated, referring to the woolly flakes on the body 
This is the largest species of Astrophytum. The five to ten, usually eight-ribbed solitary plant body has bands of white flocking, to a very variable extent, in some variants becoming near confluent. Yellowish flowers with many petals are produced at the apex of the plant.
 
Native to canyons and limestone cliffs in the Mexican states of Hidalgo, Queretaro and Guanajuato.

go to top  Blossfeldia  Werdermann 1937
Named for: Harry Blossfeld (1913 - 1986) German botanist living in Brazil. 
Blossfeldia is a genus of cacti with very small button-like bodies without ribs, tubercles or spines. Blossfeldia is probably monotypic for Blossfeldia liliputana. Several species have been described, but probably better regarded as varieties.
 
Native to the Eastern side of the Andes mountains of Bolivia and Argentina at elevations of 4,000 to 12,000 ft.
Blossfeldia is sometimes included in Parodia as Parodia liliputana (Werdermann) N.P. Taylor 1987.

Blossfeldia liliputana

Blossfeldia liliputana  Werdermann 1937
Named for: fictional country of Lilliput inhabited by a race of tiny people (Gulliver's Travels, 1726, Jonathan Swift) 
The tiny plant body less than half an inch in diameter has no rib, tubercles or spines but is dotted with areoles bearing white hairs. Unlike most other cacti, Blossfeldia liliputana has no thickened outer cuticle but instead appears to be poikilohydric (can withstand dessication). The small flowers are white or pale yellow with bright yellow stamens.
 
Native to a range from Southern Bolivia to North-Western Argentina, growing in rock crevices on cliffs. Grafting accelerates growth but produces unnatural bloated golf ball sized plants.

go to top  Cleistocactus  Lemaire 1861
Name: Greek kleistos = closed, referring to flowers that seldom open 
The genus Cleistocactus includes 50 or more species of South American columnar cacti whose tall, narrow ribbed stems have closely spaced areoles with many flexible spines giving some species a furry appearance. Stems usually branch at their base making large shrubby clumps. Their red or orange tubular flowers have exserted style and stamens but often hardly open otherwise. They tend to be produced on the sunny side of the stem.
 
Native to the mountains of Argentina, Bolivia, Peru, and Uruguay, growing at elevations of up to 9800 ft. Several other genera have been lumped into Cleistocactus, making the genus more diverse. Plants that used to be in the genus Borzicactus have flowers that open a little wider than those of the original Cleistocactus group.

Cleistocactus candelilla Cleistocactus candelilla

Cleistocactus candelilla  Cárdenas 1952
Name: Spanish candelilla = small candle  
Tubular pink-red flowers form mostly on the sunny side of the stem and are followed by pink fruits.
 
Native to the Bolivian regions of Cochabamba, Potosí and Santa Cruz and especially Amboró National Park.

Cleistocactus hyalacanthusCleistocactus hyalacanthus

Cleistocactus hyalacanthus  (K.M. Schumann) Roland-Gosselin 1904

 
Native to Argentina and Bolivia.

Cleistocactus semaipatanus
Cleistocactus semaipatanus

Cleistocactus semaipatanus  (Cárdenas) D.R. Hunt 1987
Syn. Bolivicereus samaipatanus Cárdenas 1951
Syn. Borzicactus samaipatanus (Cárdenas) Kimnach 1960
Name: grows near Samaipata in Bolivia 
The long green stems with 14 - 17 ribs can grow upright as a shrubby plant for a while but tend to become prostrate, forming a tangled mat. The closely-spaced areoles produce 13 - 40 golden spines. Attractive tubular pink to red flowers with purple stamens are produced in early Summer. These flowers open wide which is why this cactus was originally classified as a Borzicactus. The small fruits are red with white or brown wool.
 
Native to the Andean Valleys in the Department of Santa Cruz, Bolivia but common worldwide as it is used for dry landscaping in warm climates. Needs a cool Winter to flower freely.

   

Cleistocactus sepium (Kunth) A.Weber 1904
See Matucana weberbaueri

Cleistocactus smaragdiflorus

Cleistocactus smaragdiflorus  (F.A.C.Weber) Britton & Rose 1920 (Emerald Flowering Cleistocactus)
Name: Latin smaragdinus = emerald green + florus = flower 
Syn. Cleistocactus rojoi Cárdenas 1956
Named for : Leandro Rojo one of Cárdenas' field trip companions. 
The tubular red flowers with a greenish tip open minimally but the style is exserted. The green colour seems to fade as the flower opens.
 
Native to Bolivia, Paraguay and Argentina.

Cleistocactus strausiiCleistocactus strausii

Cleistocactus strausii  (Heese) Backeberg 1934 (Silver Torch Cactus)
Syn. Pilocereus straussii  
Named for: L. Straus (1862 - 1934) German merchant & cactus lover from Bruchsal, co-founder Deutsche Kakteen-Gesellschaft DKG 

 
Native to high mountain ranges of Southern Bolivia and Northern Argentina, growing above 9800 ft.

Cleistocactus tarijensisCleistocactus tarijensis

Cleistocactus tarijensis  Cárdenas 1956
Named for: Bolivian Department of Tarija 
The tubular red flowers open at their tip to produce a frilly appearance.
 
Native to Bolivia.

Cleistocactus winteri Cleistocactus winteri

Cleistocactus winteri  D.R. Hunt 1988 (Golden Rat Tail)
Syn. Borzicactus aureispinus  (F.Ritter) G.D.Rowley 1962
Syn. Hildewintera aureispina  (F.Ritter) F.Ritter 1966
Named for: Hildegarda Winter (1893-1975), sister of cactus expert Friedrich Ritter. 
This succulent plant forms mounds of tangled recumbent stems whose surface is covered with many short golden spines. The small pink flowers open more fully than those of many other Cleistocactus.
 
Native to Argentina and Uruguay. Good subject for a hanging basket. Has been hybridised with other cacti.

go to top  Copiapoa  Britton & Rose 1922
Named for: the town of Copiapó in Northern Chile. 
There are around 26 species of Copiapoa. Bodies are speroidal to columnar with ribs and a wooly apex from which yellow funnel-shaped flowers arise. Spination varies between species from strong to nearly absent and roots may be fibrous or tuberous.
 
Native to the dry coastal margin of Northern Chile, especially the Atacama desert. Rain is very infrequent but coastal fogs provide some moisture. In habitat, growth of some species is extremely slow and not much better in cultivation once past the seedling stage. Grafting speeds up growth but leads to bloated plants. Habitat plants of many species have a white bloom of waxes that protects them from ultraviolet and reduces loss of moisture, but plants grown under glass experiencing less ultraviolet may not develop this coating.

Copiapoa barquitensis

Copiapoa barquitensis  F. Ritter (1960) (nom. inval.)
Named for: Barquito = coastal town and port in Chile 
Copiapoa hypogaea  F. Ritter 1960, Copiapoa hypogaea var. barquitensis  F. Ritter 1980
Name: Greek hypogaea = underground, referring to the sunken nature of the plant body. 
This cactus forms clumps of brown to gray-green, tuberculate bodies with wooly tubercles bearing one or more short spines, often absent on older parts of the plant.
 
Native to the Atacama desert of Chile.
Photo: Holly Gate Cactus Nursery reference collection

Copiapoa humilis Copiapoa humilis

Copiapoa humilis  (Philippi) P.C. Hutchison 1953
Name: Latin humilis = low, small 
This small cactus forms clumps of brown to gray-green, tuberculate bodies with wooly tubercles bearing 7 - 13 short radial spines and 1 - 4 central spines. There is a large tap root below the body. The pale yellow flowers are scented.
 
Native to a wide range of the Atacama desert and mountain base, North and South of the type locality, Paposo, Antofagasta, Chile.

Coryphantha - RBG Kew

go to top  Coryphantha (Engelmann) Lemaire 1868 (Beehive Cactus)
Name: Greek koryphe = crown + anthos = flower 
The 57 species of cacti in the genus Coryphantha have globose bodies whose tubercles have a distinctive longitudinal groove on their upper surface. The spine cluser may have a central spine but this is a variable feature. Flowers in pink or yellow form at the growing apex of the plant followed by seeds with a reticulate (net-like) surface.
 
Members of this genus are widely distributed from the US state of Montana across the Southern states into Mexico and central America.

Coryphantha calipensis - RBG Kew

Coryphantha calipensis  H. Bravo Hollis 1992
Name: refers to the small town of Calipan in the Mexican State of Puebla 
Flowers are yellow.
 
Photographed at RBG Kew.

Coryphantha echinus

Coryphantha echinus  (Engelmann) Britton & Rose 1923 (Texas Pincushion)
Syn. Mammillaria echinus  Engelmann 1856
Name: Greek ekhinos = hedgehog, sea urchin 
The solitary globular plant body has areoles with 16 - 30 thin radial spines and 0 - 4 stout central spines. In young plants the central spines are absent, only developing with age. The large flowers are bright yellow with golden stamens and are folllowed by green ovoid fruit.
 
Native to West Texas and the Mexican states of Coahuila, Chihuahua, growing on limestone soils.
Photo: Los Caballos, Brewster County, Texas.

go to top  Echinocactus  Link & Otto 1827
Name: Greek echinos = spiny + cactus 
One of two genera of classic barrel cactus with 6 species. Plant bodies have deep ribs with heavy spination and relatively small flowers. The ovaries and fruits are distinctively woolly although the flower tube is scaly.
 
The best known member of the genus is the Mexican Echinocactus grusonii (Golden Barrel). Through habitat destruction, the wild plant has become rare and endangered. However, it is exceeding common in the hortultural trade and propagated from seed in very large numbers.

Echinocactus grusonii

Echinocactus grusonii  H. Hildmann 1886 (Mother in Law's Cushion, Golden Barrel Cactus)
Named for: Hermann August Jacques Gruson (1821 - 1895) German engineer & cactus collector 
The spherical green plant body of a mature plant has up to 35 prominent ribs edged with golden-yellow spines. Young plants have somewhat tuberculate ribs. With age, the body may become 4 ft in height and more cylindrical. Mature plants can offset to form a small clump. As with other barrel cacti, the body tends to lean to the south or southwest so that the spines can better filter the fierce sunlight. Selected cultivars are known with white spines or without spines. Yellowish hairs produced from the areoles form a wooly mat around the top of a mature plant.

Echinocactus grusonii seedlings
Above: E. grusonii seedlings
Echinocactus grusonii spineless form
E. grusonii spineless form

A ring of small (for the size of the plant) yellow flowers are produced around the wooly crown in late Spring or early Summer and are followed by small yellowish fruits terminated by the dried flowers. Fruits are full of small brown seeds from which it is easy to grown new plants. Seedlings are initially bi-lobed.
 
Echinocactus grusonii is native to the Mexican states of Querétaro and Zacatecas. Much of the population was lost when the Zimapán Dam and reservoir was built in Hidalgo although conservationists rescued many of the plants. Echinocactus grusonii is a popular feature plant for dry landscaping in warm climates.

Echinocactus horizonthalonius - Maverick Mountain, Texas
Above: Maverick Mountain
 
Echinocactus horizonthalonius - Chisos Mountains, Texas
Above: In front of Chisos Mountains baisin window pour-off

Echinocactus horizonthalonius  Lemaire 1839 (Eagle's Claw, Devil's Head)
Name: Latin horizonthal = horizontal + halos = flat 
The blue-green flattened-globose to cylindrical body is always solitary with typically 8 ribs. The areoles have 5 - 7 radial spines recurved against the body and 3 - 5 erect radial spines. The spiny cage surrounding the plant body often persists after death of the plant and can sometimes be found rolling around in the wind. Flowers are pale pink to magenta with a wooly floral tube, produced in late Spring to early Summer followed by fruits covered in wool.

Echinocactus horizonthalonius - Maverick Mountain, Texas

Native to the Chihuahuan Desert from Arizona, New Mexico, Texas and into North-Eastern Mexico and quite common in places. Delightful plants in their habitat but very difficult and slow-growing in cultivation.
 
Left: This specimen of Echinocactus horizonthalonius had rather short stubby spines compared to the rest of the population in the same area. Maverick Mountain, Texas.

Echinocactus platyacanthus

Echinocactus platyacanthus  Link & Otto 1827
Syn. Echinocactus ingens  Zuccarini ex Pfeiffer 1837
Name: Greek platyacanthus = with wide thorns 
This barrel cactus eventually grows larger than any other, up to 8 ft tall and 5ft wide.
 
Widely-distributed across North-East and Central Mexico.

Echinocactus polycephalus - Death Valley California. Echinocactus polycephalus - Death Valley California.

Echinocactus polycephalus  Engelmann & J.M. Bigelow 1857
This one of the few barrel cacti that can clump up by offsetting. Large many-headed clumps of this cactus are seen in the hot, dry mountains surrounding Death Valley.
 
Native to a wide range across the deserts of the USA South-West states of Texas, Arizona, Nevada, California and into Northern Sonora, Mexico.
Photos: Death Valley, California.

Echinocactus texensis

Echinocactus texensis  Hopffer 1842 (Horse Crippler, Devil's Pincushion)
Syn. Homalocephala texensis  Britton & Rose 1923
Name: texensis = originates in Texas 

 
Native to Texas, South-Eastern New Mexico, Olkahoma and the North-Eastern Mexican states of Coahuila, Southern Nuevo León, Durango and Tamaulipas.
Photo: Garden of the Judge Roy Bean Museum & Visitor Centre at Langtry. In its habitat, the top of the cactus is usually flush with the soil.

go to top  Echinocereus  Engelmann 1848 (Hedgehog Cacti)
Name: Greek echinos = spiny + Latin cereus = candle 
Echinocereus have globular or short columnar bodies with deep ribs, often clumping up by basal offsetting with age. The strong spination, arranged along the apex of the ribs, covers the body and may be quite colourful. The flowers are bright reds, pinks and yellows and quite large in some species.
The monotypic genus Morangaya and some species from Wilcoxia have been transferred into Echinocereus.

Echinocereus berlandieri

Echinocereus berlandieri  (Engelmann) J.N. Haage 1859

 
Photo: Holly Gate Cactus Nursery reference collection

Echinocereus chloranthus, Los Caballos

Echinocereus chloranthus  (Engelmann) J.N.Haage 1859 (Green Flowered Torch Cactus)
Syn. Echinocereus viridiflorus subsp. chloranthus  (Engelmann) N.P.Taylor 1997
Name: Greek chlor = green + anthus = flower 
This variable cactus has flowers ranging from green, brown or wine-coloured and dense spination ranging from white to reddish brown. Native to Western Texas, South-Eastern New Mexico, and Northern Mexico, growing on igneous soils.
Photo: Los Caballos, Brewster County, Texas.

Echinocereus coccineus

Echinocereus coccineus  Engelmann 1848 (Strawberry Hedgehog)

 
Native to South-Western USA, Arizona, California, Colorado, New Mexico, Nevada, Utah, Texas and the Mexican states of Coahuila, Chihuahua and Sonora.

Echinocereus dasyacanthus

Echinocereus dasyacanthus  Engelmann 1848 (Texas Rainbow)
Syn. Echinocereus pectinatus var. dasyacanthus  (Engelmann) W. Earle ex N. P. Taylor 1984
Name: Greek dasys = thick + akanthos = thorn 
This cactus forms short columns, occasionally offsetting at the base of higher up. The stem has 15 - 20 ribs but these are largely obscured by the dense bristly spines. Areoles produce 16 - 24 radial and 3 - 10 short central spines which vary in colour from white, pale yellow to browns and purple, depending on the growing conditions. Annual growth rings are often marked by spines of different colours. The large yellow flowers with a greenish throat and green stigma make this an exceptionally attractive species. The outer petals may have a darker mid-stripe.
 
Native to the Chihuahuan desert, Texas, Oklahoma, Southern New Mexico and Northern Mexico, usually on limestone soils. Photo: Limestone cliffs near Terlingua.

Echinocereus engelmannii - Holly Gate Cactus Nursery reference collection

Echinocereus engelmannii  (Parry ex Engelmann) Lemaire 1868

 
Photo: Holly Gate Cactus Nursery reference collection

Echinocereus enneacanthus - Big Bend National Park

Echinocereus enneacanthus  Engelmann 1848
The soft, green stems initially grow upright, becoming recimbent as they lengthen and offsetting from their base to produce a sprawling clump with a flabby appearance. Stems have 7 - 12 ribs with well-spaced areoles bearing 5 - 9 curved radial spines and 1 - 3 short central spines. In the Spring bright-pink to reddish diurnal flowers are produced. The edible fruits are yellowish-green to reddish and furnished with glochids.
 
Native to Chihuahuan deserts of New Mexico, Texas and the Northeastern Mexican states of Chihuahua, Coahuila, Durango, Nuevo León, San Luis Potosí and Sonora.
Photo: Big Bend National Park

Echinocereus lauii - cultivated, flower

Echinocereus lauii  G. Frank 1978
Named for: Dr. Alfred Bernhard Lau (1928 - 2007) German missionary and cactus enthusiast. 
This small cactus clumps up by offsetting from its base. The green ribbed stems are mostly obscured by the 20 radial spines and white hairs from each areole. Areoles also produce four central spines. Pink funnel-shaped flowers are followed by spherical greenish spiny fruits.
 
Native to the Mexican state of Sonora.

Echinocereus pectinatus

Echinocereus pectinatus  (Scheidweiler) Engelmann 1848 (Texas Rainbow)
Name: Latin pectinatus = comb-like referring to the spines 
The short columnar green body is usually solitary but old plants may branch. There are up to 30 white to pink radial spines but the central spines are absent or a few very short ones. The funnel-shaped flower is bright pink and followed by a purple-green fruit with dehiscent spines.
 
Native to South-Western USA, Texas, New Mexico.
Echinocereus pectinatus var. dasyacanthus (Engelmann) W. Earle ex N. P. Taylor 1984
is a taller columnar plant with a large yellow flower.

Morangaya pensilis - Holly Gate Cactus Nursery reference collection

Morangaya  G.D. Rowley 1974
Named for: Dr. Reid Moran and Ed & Betty Gay who provided plants and information about the species. 
The monotypic genus Morangaya has been merged into Echinocereus.

Echinocereus pensilis  (Brandegee) J.A. Purpus 1908
Syn. Morangaya pensilis  (K. Brandegee) G.D. Rowley 1974
 
Photographed at Holly Gate Cactus Nursery reference collection

Echinocereus polyacanthus

Echinocereus polyacanthus  Engelmann 1848 (Giant Claret Cup)
Syn. Echinocereus triglochidiatus var. polyacanthus (Engelmann) Benson 1944
Name: Latin polyacanthus = many spined 
This variable species forms large clumps of dozens of stems, producing bright red blooms with whiteish throats and rounded petals in Spring to early Summer.
 
Native to South-Eastern Arizona, Western New Mexico, North-Western Mexico including Baja California.

Echinocereus x lloydii - N. of Marathon, Texas

Echinocereus roetteri var. lloydii  (Britton & Rose) Backeberg 1960
Syn. Echinocereus x lloydii  Britton & Rose 1922,  Echinocereus x roetteri  (Engelmann) Rümpler 1866
 
This rare plant is probably a natural hybrid Echinocereus pectinatus var. dasyacanthus x Echinocereus coccineus and as such, individual plants may present a variable appearance.
 
Photographed: N. of Marathon, Texas.

Echinocereus stramineus - Dog Canyon, Big Bend National Park
Echinocereus stramineus - Big Bend National Park

Echinocereus stramineus  (Engelmann) F. Seitz 1870 (Strawberry cactus)
Name: Latin stramineus = made of straw 
The many light-yellow spines make this clumping cactus look like a pile of old straw, distinguishing it from other Echinocereus, especially the otherwise similar E. enneacanthus. The light green stems have 11- 17 ribs with areoles bearing 7 - 10 radial and 2 - 4 central spines, largely obscuring the plant body. The bright pink flowers with yellow stamens and green stigma are produced in the Spring and are followed by juicy red fruit. Occasional white flowered plants have been reported in the Big Bend National Park.
 
Left: Dog Canyon, Big Bend National Park, Texas.
 
Native to Trans-Pecos Texas and the Big Bend Country, New Mexico and the Mexican states of Coahuila, Chihuahua, and Nuevo León. The edible fruit are picked and sold in Mexican markets.

 
Left: Big Bend National Park, Texas, April 1993.

Echinocereus triglochidiatus, Los Caballos Echinocereus triglochidiatus, Los Caballos

Echinocereus triglochidiatus  Engelmann 1848 (Claret Cup)
Name: Latin tri = three + glochidium = barbed hair or spine 
The green body has prominently tuberculate ribs. Despite the name, areoles often have more than 3 straight to curved spines. The grey radial spines (1 - 10) and central spines (1 - 4) are hard to tell apart. This widespread clumping cactus has several named varieties. However, considerable variation may be seen between adjacent clumps. The dark red to orange funnel-shaped flowers, sometimes with a pale base, have pink to purple stamens and a green stigma. Flowers are followed by juicy, edible yellow-green to pink fruit.
 
Native to Arizona, Southern California, Colorado, New Mexico, Nevada, Utah, Texas, and Mexico, growing on the desert floor and at elevations of up to 11,000 ft above sea level on both igneous and limestone soils. Seen flowering on the top of Emory Peak in the Chisos Mountains.
Photos: Los Caballos, Brewster County, Texas. Note: ants feeding on nectar in the left-hand picture.

Echinomastus  Britton & Rose 1922
Name: Greek echinos = spiny + mastos = breast, referring to the tubercles. 
This genus includes 5 - 9 species of globular to short cylindric cacti with dense spination obscuring the plant body. Stems have grooved tubercles which are sometimes glandular. Diurnal cream, pink to red and brownish flowers are produced from the tips of tubercles near the top of the plant.
 
Native to the South-Western USA and Northern Mexico. Several former species are now regarded as synonyms.
Some authors include this genus in Sclerocactus.

Echinomastus intertextus

Echinomastus intertextus  (Engelmann) Britton & Rose 1922 (Chihuahua Pineapple Cactus)
Syn. Neolloydia intertexta  (Engelmann) L.D. Benson 1969
Syn. Sclerocactus intertextus (Engelmann) N.P. Taylor 1987
Name: Latin intertextus = interwoven, referring to the spines 
The solitary globular to ovoid plant body with 11 - 13 tuberculate ribs is largely hidden by the interwoven spines. Areoles produce 13 - 25 curved white radial spines and 4 pink to grey central spines. The funnel-shaped flowers are pink or white and followed by spherical green fruit.
 
Native to a range from South-Eastern Arizona to West Texas and the Mexican states of Chihuahua and Sonora.
Photo: Growing on granite soil in front of Chisos Mountains, South of Panther Junction.

go to top  Echinopsis  Zuccarini 1837 (Hedgehog Cactus)
Name: Latin echinos = hedgehog or sea urchin + cacti, referring to the often dense spination 
As currently constituted, the genus Echinopsis includes over 128 species of South American cacti with prominment ribs, ranging from small globular plants to tree-like cacti. Flower stems are longer than in Echinocactus and the short-lived relatively large funnel-shaped flowers have wooly, hairy or scaled tubes. Flowers are followed by pulpy fruit which may have a hairy skin.
 
Native to gravelly soils and rocky hillsides across South America (Argentina, Bolivia, Brazil, Chile, Ecuador, Paraguay, Peru, and Uruguay). Many former members of former genera e.g. Lobivia, Mediolobivia, Rebutia, Trichocereus have been lumped into Echinopsis. Inter-specific hybridisation is easy within this group and many free-flowering hybrids have been produced.
 
Lobivia   Britton & Rose 1922   Lobivia has been merged into Echinopsis.
Name: an anagram of Bolivia 
The genus includes 20 species of small globular plants from the highlands of Bolivia, Peru and Argentina. The bee-pollinated flowers are brightly coloured with relatively short flower tubes.
 
Trichocereus  (Berger) Riccobono 1909 (Torch Cacti)   Trichocereus has been merged into Echinopsis.
Name: Greek trikhos = hair or bristle + Latin cereus = candle 
Trichocereus is a group of about 30 columnar plants, which may be erect or decumbent with one hanging epiphytic species. Some Trichocereus become very large and tree-like. Flowers are typically white and very large with long flower tubes, opening at night for pollination by bats and moths. Native to Argentina, Bolivia, Chile and Peru. Some species produce toxic psychoactive alkaloids.

Echinopsis backebergii Echinopsis backebergii

Echinopsis backebergii  Werdermann 1931
Syn. Lobivia wrightiana  Backeberg 1937,  Lobivia backebergii  (Werdermann) Backeberg 1935 subsp. wrightiana (Backeberg) G.D. Rowley 1982
Named for: Curt Backeberg (1894 - 1966) German collector and classifier of cacti. 
Two subspecies are recognised: Echinopsis backebergii backebergii and Echinopsis backebergii wrightiana which some consider to be separate species. This solitary or clumping cactus has a globular green body with 15 ribs, becoming cylindrial with age. The areoles have 1 - 11 brown spines. The funnel-shaped flowers are pink to red with a white throat.
 
Native to the Andes mountains of Eastern Bolivia and Southern Peru, growing at up to 9800 ft above sea level.
 
 
Left: Echinopsis backebergii subsp. wrightiana  (Backeberg) M. Lowry 2005
Syn. Lobivia wrightiana  Backeberg 1937
has very long thin spines and pale lilac flowers with a paler throat.
Native to Huancavelica, Central Peru.

Lobivia wrightiana
Echinopsis chamaecereus

Echinopsis chamaecereus  H. Friedrich & Glaetzle 1983 (Peanut Cactus)
Syn. Chamaecereus silvestrii  (Spegazzini) Britton & Rose 1922
Named for: Filippo Silvestri (1873-1949) Italian entomologist & botanist. 
This mat-forming cactus has many long thin stems, initially erect but later decimbent, with 8 - 10 ribs profusely furnished with clusters of 10 - 15 small, bristly, radial spines. Peanut-sized offsets are produced along the main stems, detaching rather easily to start new plants. Funnel-shaped orange flowers are produced freely in late Spring and sporadically later on.
 
Native to the Andean mountains of Argentina and moderately frost-hardy when dry. Features in many colourful hybrids with other Echinopsis, especially Lobivia species with the hybrids known as Chamaelobivia. Echinopsis chamaecereus f. aureus is a yellowish chlorophyll-deficient mutant commonly seen grafted.

Echinopsis comarapana

Echinopsis comarapana  Cárdenas 1957
Name: from Comarapa in the Bolivian province of Vallegrande. 
This cactus has short cylindrical gray-green stems with ten - twelve ribs bearing grayish areoles with one central spine and 9 - 11 thin radial spines. By offsetting, this cactus clumps up to form large cushions. The relatively-large flowers are white and funnel shaped.
 
Native to the Bolivian department of Santa-Cruz.

Echinopsis formosa

Echinopsis formosa  (Pfeiffer) Jacobi ex Salm-Dyck 1850
Name: Latin formosa = well formed, handsome 
A commonly solitary cactus, offsetting from the base with maturity. The light-green body has 27 - 50 ribs with areoles producing 9- 15 slightly curved radial spines and 2 - 9 brown central spines. The funnel-shaped flowers are bright yellow, orange to red.
 
Native to Argentina and Chile.

Echinopsis huaschaEchinopsis huascha

Echinopsis huascha  (Weber) Friedrich & G.D.Rowley 1974 (Red Torch Cactus, Argentine Hedgehog)
Named for: location in North-Western Argentina. 
This cactus grows upright at first, then becomes decumbent as the spiny, ribbed stem elongates. Stems typically have 14 - 17 ribs and areoles with 9 - 11 radial spines and 1 - 3 needle-like brown central spines. Basal offsetting produces a mat of sprawling stems. Flower colours range from golden-yellow to orange and red. Flower tubes are scaly with long brown hairs.
 
Native to Argentina and Bolivia.

Echinopsis pygmaea

Echinopsis pygmaea  R.E. Fries 1905
Syn. Lobivia pygmaea  (R. E. Fries) Backeberg 1935,  Mediolobivia eos var. roseiflora  Rausch 1972,  Rebutia pygmaea  (R. E. Fries) Britton & Rose 1922

 
This variable species has many (>60) synonyms. Current fashion favours Echinopsis.
Native to Bolivia and Argentina.

Echinopsis schieliana

Echinopsis schieliana  (Backeberg) D. R. Hunt 1987
Syn. Lobivia schieliana Backeberg 1957
Named for: German cactophile Wolfgang Schiel (1904-1978) 
This small cactus forms clumps of dark reddish-green globose to cylindrical bodies, spidery golden spines and light red or dark gold flowers.
 
Native to a small area of North-West Bolivia (La Paz) and Peru, at altitudes arouind 10,000 ft above sea level.

Echinopsis spiniflora

Echinopsis spiniflora  (K. Schumann) A.Berger 1929
Syn. Acanthocalycium spiniflorum  (K. Schumann) Backeberg 1935
This cactus is usually solitary but may offset at its base. The dark green globular body has 9 - 15 ribs with areoles covered in brownish fluff and producing dark 5 - 10 brown to grey radial spines and 1 - 4 central spines. Flowers are white or shades of pink with yellow stamens. Flower buds and floral tubes are very hairy and scaly.
 
Native to Argentina.

Echinopsis aff. strigosa Echinopsis aff. strigosa

Echinopsis aff. strigosa  (Salm-Dyck) Friedrich & G.D.Rowley 1974

 
Native to Argentina.

Echinopsis thelegona Echinopsis thelegona

Echinopsis thelegona  (Weber) Friedrich & G.D. Rowley 1974
Syn. Trichocereus thelegonus  (Weber) Britton & Rose 1920
The spiny ribbed stems are about 3 inches in diameter and columnar, then decumbent as the stems elongate. Areoles have 6 - 7 radial spines and 1 central spine. The large fragrant flowers are white, opening at night and are followed by edible red fruit.
 
Native to low deserts of North-Western Argentina and Bolivia.

go to top  Escobaria  Britton & Rose 1923 (Pincushion Cactus, Foxtail Cactus)
Named for: Rómulo Escobar Zeeman (1882 - 1946) & Numa Pompilio Escobar Zerman (1874 - 1949), Mexican agronomists 
Escobaria is a genus of 23 species of small cacti native to North America. The plant bodies are flattened spheroids to short cylindrical columns, without ribs but with prominent tubercles which may become corky and shrivel with age. Spines are never hooked. Flowers in white, yellow pink or purple are produced near to the growing point. Escobaria are similar to Coyphantha but their seeds have a pitted surface rather than a reticulate one.
 
Native to a large range from Canada into Northern Mexico. A single species is native to Cuba.

Escobaria albicolumnaria

Escobaria albicolumnaria  Hester 1941 (Silver-Lace Cob Cactus)
A solitary cactus growing as a short column up to 10in tall. Plants occasionally branch and becomemulti-stemmed. Tubercles are grooved. Areoles produce 25 - 30 white radial spines and 11- 15 central spines. The small flowers are pink with a darker mid-stripe on the petals and are followed by yellowish-green fruits.
 
Native to limestone of Brewster County, Texas
Photo: On limy conglomerate above Boquillas Canyon, Big Bend National Park, Texas.

Escobaria hesteri

Escobaria hesteri  (Y. Wright) Buxbaum 1951

 
Photo: South of Marathon, Texas.

Escobaria missouriensis

Escobaria missouriensis  (Sweet) D.R. Hunt 1978

 
Photograph: Robin Howard, Cheyenne Mountain State Park, Colorado. June 2008

Escobaria tuberculosa - West of Terlingua

Escobaria tuberculosa  (Engelmann) Britton & Rose 1923
This is the type species for the genus.
 
West of Terlingua, Texas.

Escobaria tuberculosa - Dog Canyon, Big Bend National Park

Escobaria tuberculosa  (Engelmann) Britton & Rose 1923

 
Photo: Dog Canyon, Big Bend National Park, Texas.

Escobaria strobiliformis seedlings Escobaria tuberculosa - cultivated

Escobaria tuberculosa  (Engelmann) Britton & Rose 1923
 
Photos: cultivated plants.

Escobaria vivipara

Escobaria vivipara  (Nuttall) Buxbaum 1951 (Spinystar Cactus)

 
Native to a wide range of Northern America from Canada into Mexico.
Photo: Escobaria vivipara in fruit. Marathon, Texas.

go to top  Ferocactus  Britton & Rose 1922
Name: Latin ferox = fierce + cactus 
The genus Ferocactus includes about 25 species of large barrel cacti with deeply ribbed bodies and strong spines. With age, some species form 10ft columns. Ribs may be straight or tuberculate. The yellow or red flowers are produced around the growing point and are relatively small for the body size. Flower buds are scaly without spines or hairs. The typically-elongated yellow fruits contain many hard black or brown seeds.
 
Native to the South-Western USA and North-Western Mexico. Many Ferocactus species have extrafloral nectaries above each areole. The nectar is attractive to ants which form colonies around the base of the plant and in return for nectar, help to protect the cactus and keep it clean. However, in cultivation sugary nectar exuded from the nectaries makes Ferocacti prone to black mould.

Ferocactus acanthodes cristate - Arizona

Ferocactus acanthodes  Britton & Rose 1922
Syn. Ferocactus cylindraceus  (Engelmann) Orcutt 1926

 
This dustbin-sized Ferocactus has developed a cristate growing point. Nevertheless, it is still flowering and producing fruits.
Photographed in Arizona 2004.

Ferocactus haematacanthus - Texas

Ferocactus haematacanthus  (Monville ex Salm-Dyck) Bravo ex Backeberg & Knuth 1935 (Texas Barrel)
This is the only barrel cactus native to Texas, reaching a height of about 4 ft. The solitary globular green body has 13 - 17 ribs with closely-spaced areoles bearing 6 - 7 radial spines and 4 long hooked central spines.
 
Native to the Chihuahuan Desert of South-Western Texas, New Mexico and North-Western Mexican states of Puebla and Veracruz, usually on limestone soils.
Photo: Black Gap Wildlife Management Area, Texas.

Ferocactus glaucescens Ferocactus glaucescens

Ferocactus glaucescens  (de Candole) Britton & Rose 1922 (Blue Barrel Cactus)
This strongly-ribbed cactus can remain solitarry or with maturity form large clumps by basal offsetting. Spination seems variable from 6 - 7 radial and 1 central spine, to no spines (forma nuda). The yellow, funnel-shaped flowers are quite long lasting. Petal margins are irregular.
 
Native to the Mexican state of Hildago, growing among limestone rocks in juniper woodland at up to 4000ft above sea level.

Ferocactus pilosus

Ferocactus pilosus  (Galeotti ex Salm-Dyck) Werdermann 1933 (Mexican Lime Cactus, Mexican Fire Barrel)
This large, solitary or clumping barrel cactus has a strongly ribbed, bright green body contrasting with strong red central spines. Radial spines are either absent or reduced to white fibres which on some plants may be plentiful. Becoming columnar (8ft) with age, this cactus may offset low down to form a group of short columns. Flowers are red to yellow with a scaly ovary and are followed by yellow fruit.
 
Native to limestone soils over a wide range in the Mexican states of Nuevo León, San Luis Potosí, Coahuila and Zacatecas.

go to top  Gymnocalycium  Pfeiffer ex Mittler 1844
Name: Greek gymno = naked + kalyx = bud 
Gymnocalycium includes about 70 species of small globose, usually solitary cacti. Flower buds are smooth and scaled without spines or hairs.
 
Native to Argentina, Southern Bolivia, Brazil, Paraguay and Uruguay. These cacti are popular for their brightly coloured flowers.

Gymnocalycium achirasense - Holly Gate Cactus Nursery reference collection

Gymnocalycium achirasense  H.Till & Schatzl 1987
Syn. Gymnocalycium monvillei  Pfeiffer ex Britton & Rose subsp. achirasense (H.Till & Schatzl) H.Till 1993

 
Native to Northern Argentina.
Photo: Holly Gate Cactus Nursery reference collection

Gymnocalycium friedrichii

Gymnocalycium friedrichii (Werdermann) Pazout 1964 (invalid name)
Syn. Gymnocalycium mihanovichii  Frič ex Gürke) Britton & Rose 1922

 
Native to Bolivia, Paraguay and Argentina.

Gymnocalycium gibbosum

Gymnocalycium gibbosum   (Haworth) Pfeiffer ex Mittler 1844
This is the type species of the genus Gymnocalycium.
 
Native to Argentina.

Gymnocalycium lafeldense = bruchii

Gymnocalycium lafeldense  Vaupel 1924
Syn. Gymnocalycium bruchii   (Spegazzini) Hosseus 1926

 
Native to Western Argentina.

Gymnocalycium monvillei ssp.horridispinum

Gymnocalycium monvillei ssp. horridispinum  (G.Frank ex H.Till) H.Till 1993
Syn. Gymnocalycium horridispinum  G.Frank ex H.Till 1987
Named for: M. Chevalier de Monville (1794 - 1863) French botanist 

 
Native to Argentina.

Gymnocalycium parvulum

Gymnocalycium parvulum  Spegazzini 1925
Name: Latin parvulum = very small 
This is a small plant whose greenish-brown body has 9 - 13 ribs with areoles producing 5 - 7 radial spines and no central spines. The funnel-shaped flowers are white with a reddish-purple throat.
 
Native to Argentina.

Gymnocalycium pflanzii

Gymnocalycium pflanzii  (Vaupel) Werdermann 1935
Named for: Karl Pflanz (1872-1925) German botanist and plant collector. 

 
Native to Bolivia, Paraguay and Argentina.

Gymnocalycium saglionis Gymnocalycium saglionis

Gymnocalycium saglionis  (Cels) Britton & Rose1922
Named for: Joseph Saglio, French cactus collector 
This solitary barrel cactus has a dark green body up to 3ft tall and with 10-30 ribs. Areoles produce 10 - 15 red to black radial spines recurved towards the body and 1 - 3 curved central spines. Pale pink to white flowers are produced in a ring around the top of the plant thoughout the growing season. the globular red fruit are spontaneously dehiscent, revealing many dark brown seeds.
 
Native to Northern Argentina.

go to top  Lophophora  J.M. Coulter 1894 (Peyote Cactus)
Name: Greek lophos = crest + phoreo = to carry 
The genus Lophophora includes up to 4 species of bluish-green to gray button-like cacti with 5 - 8 ribs, whose spines have degenerated into tufts of hairs from each areole.The plant is supported by a large taproot. With age, individual heads can reach 6 in across and can offset at their base to form a clump. Flowers are produced from the growing point and as these plants are self-fertile, may be followed by elongated pink fruit.
 
Native to a range from South-Western USA into central Mexico. In cultivation they are quite free-flowering. These cacti, especially Lophophora williamsii, contain mescaline, pellotine and other toxic alkaloids and feature in Indian-American rituals. This is the "Divine Cactus" as described by Anderson.

Lophophora williamsii Lophophora williamsii

Lophophora williamsii  (Lemaire ex Salm-Dyck) J.M. Coulter 1894
Named for: Sir. C.H. Williams, British Ambassador to the state of Bahia, Brazil 
The plant body is a blue-gray button divided into ribs by incised lines and with tubercles marked by tufts of wool. Small pink flowers are freely-produced from the centre of the body. The root is a thick tap-root.
 
Photos: West of Terlingua, Texas.

go to top  Mammillaria  Haworth 1812 (Nipple Cactus)
Name: Latin mammilla = nipple, referring to the distinctive tubercles. 
The large genus Mammillaria includes 171 species of small cacti with distinctive tuberculate aereoles, the apex of which bears spines and the base of which is spineless but may be woolly or have bristles. The base of the aereole also bears the flowers and fruits. The spines are quite variable between species and may be straight or hooked. Most species are spheroidal, or with age form short columns up to 8 inches tall. Many species have small pink flowers, or small yellow or white flower. Just a few have relatively large showy flowers. Flowers are typically folllowed by small, tubular red fruit.
 
Most Mammillaria are native to Mexico but also to the South-Western USA, the Caribbean islands, Colombia, Guatemala, Honduras, and Venezuela. This genus of cacti is popular and easy in cultivation and many species flower freely on a sunny window ledge.

Mammillaria bocensis

Mammillaria bocensis  Craig 1945
Name: found near to Las Bocas, Sonora, Mexico 
The globose to cylindrical dark green body mostly remains solitary but old plants may cluster. Each tubercle produces 6 - 8 radial spines with reddish-brown tips and a single central spine. Flowers are greenish-yellow to pale pink with a darker brownish stripe along the petals and a bright green style. They are followed by club-shaped red fruit.
 
Native to the Mexican states of Sonora, Sinaloa, Jalisco and Nayarit, growing in coastal salty flats and scrub and up to 300ft above sea level.

Mammillaria bocasana (pink flower) - cultivated
M. bocasana (pink flower)
Mammillaria bocasana (intermediate flower)
M. bocasana (intermediate flower)
Mammillaria bocasana (yellow flower) - cultivated
M. bocasana (yellow flower)
 

Mammillaria bocasana  Poselger 1853 (Powder Puff Cactus)
Name: found in Sierra de Bocas Mountain range, San Luis Potosí, Mexico 
This popular fast-growing, clumping cactus has bluish green tuberculate stems that are mostly obscured by clusters of long silky white hairs and a single (rarely two) long reddish-brown fish-hook spine from each tubercle. Flowers may be pink or yellow and are followed by cylindrical pink fruit. There are several selected cultivars with differing amounts of hairs and flower colour.
 
Native to the central Mexican states of San Luis Potosi, Queretaro and Zacatecas at altitudes of up to 7500 ft above sea level. This is a very easy freely-flowering cactus to grow and if potted on will soon form a nice clump. It is best watered from below as the silky white hairs become matted otherwise.
There is a cristate form of Mammillaria bocasana which continues to flower nicely with pink flowers along the crest. Mammillaria bocasana cv. Fred is a monstrose cultivar that over time has diversified into several clones with weird shapes.

Mammillaria candida Mammillaria candida

Mammillaria candida  Scheidweiler 1838 (Snowball cactus)
Syn. Mammilloydia candida  (Scheidweiler) Buxbaum 1951
Syn. Neomammillaria candida (Scheidweiler) Britton & Rose 1923
Name: Latin candida = white 
This globular cactus, becoming cylindrical with age, is covered with fine white hair and many short, white or brown spines. Each tubercle can produce as many as 120 radial spines. Old plants can form large clumps. The flowers are pale yellow to pale pink with a darker stripe along the middle of the petals.
 
Native to the Mexican states of Coahuila, Nuevo León, San Luis Potosí and Tamaulipas, growing on limestone soils and rocks at altitudes of 1,600 - 8,200 ft above sea level. In cultivation, ground limestone can be added to the soil.

Mammillaria dixanthocentra

Mammillaria dixanthocentron  Backeberg 1963
Name: Greek di = two + xanthos = yellow + kentron = center, referring to the two central spines 
The globose dark green body is obscured by 19 - 20 white radial and 2 -4 white to brown central spines with dark tips. Some cultivated forms have been selected for exceptional length of the central spines and different spine colours. The small flowers are pink to red and are followed by orange club-shaped fruit.
 
Native to the Mexican states of Oaxaca and Puebla at altitudes of up to 6500 ft in dry deciduous forests and clinging to cracks in rocks.

Mammillaria elongata

Mammillaria elongata  De Candole 1828 (gold lace cactus, ladyfinger cactus)
Name: Latin longus = long, referring to elongated stems 
The cylindrical stems have spirally-arranged conical tubercles with 14 - 25 golden radial spines and few or no central spines. The interlocking spines form a mesh covering the stems. Many small cream-coloured flowers (sometimes flushed with pink) are produced in the Spring and are followed by cylindrical red fruit. As the stems elongate they become prostrate. Roots are fibrous.
 
Native to the central Mexican states of Hildago, Guanajuato, and Queretaro. Named cultivars have been selected on the basis of different spine colours from dark brown to white, and a cristate form is sometimes seen.

Mammillaria formosa

Mammillaria formosa  Galeotti ex Scheidweiler 1838
Name: Latin formosa = well designed 
The globose green bodies have prominent tubercles with 2 - 6 central spines and very fine radial spines. Axils are woolly, especially around flowers. Flowers are pale pink with a darker stripe along the middle of the petals. By dichotomous division of plant bodies and offsetting, this species can form large clumps.
 
Native to the Mexican states of Coahuila, Aguascalientes, Guanajuato, Zacatecas, Tamaulipas, Nuevo León and San Luis Potosí, Mexico.

Mammillaria glassii - cultivated

Mammillaria glassii R.A. Foster 1968
Named for: Charles Edward Glass (1934-1968) American horticulturalist & plant collector 
This small mat-forming cactus offsets freely to form fluffy white clumps. The short globose stems have areoles that produce 50 - 60 hair-like radial spines and 1 - 4 hooked or straight central spines. The axils also produce 10- 20 white bristles. The small, funnel-shaped flowers are pale yellow to pale pink and are followed by bright red, oval fruit filled with black seeds.
 
Native to the Sierra Madre Oriental mountain range across the Mexican states of Coahuila, Nuevo León and Tamaulipas, growing at altitudes of 4750 - 7400 ft above sea level. If kept dry, will tolerate light frost.

Mammillaria gracilis - cultivated

Mammillaria gracilis  Pfeiffer 1838
Syn. Mammillaria vetula subsp. gracilis (Pfeiffer) D.R. Hunt 1997
Small (1 - 2 in long) cylindrical green bodies are covered with white spines with 11 - 16 radial spines and 0 - 5 central spines from each areole, with centrals especially on mature stems. The stems offset freely along their length. Offsets detach very easily, but every one will root and form a new plant. The small pale yellow flowers have a darker mid-stripe and are followed by pink fruit.
 
Native to the Mexican states of Hilalgo and Queretaro,growing at up to 6000 ft above sea level. This cactus certainly tolerates some frost if dry, but not cold-wet conditions.
Various selected spine variants are in cultivation e.g. "Arizona Snowflake / Snowcap".

purple-dyed Mammillaria gracilis

Mammillaria gracilis, possibly the cultivar "Arizona Snowflake / Snowcap"
dyed purple and marketed under the trade name Kosmic Kaktus.
A range of other colours are available. New growth will have the gleaming
white spines of the original plant so if you buy one of each colour, those
that grow will eventually all look the same.
 
Photo: Andrea Hüper, 2014.

Mammillaria grusonii - Holly Gate Cactus Nursery reference collection

Mammillaria grusonii  Runge 1889
Named for: Hermann August Jacques Gruson (1821 - 1895) German engineer & cactus collector 

 
Native to the Mexican states of Coahuila and Durango.
Photo: Holly Gate Cactus Nursery reference collection

Mammillaria haageana Mammillaria haageana

Mammillaria haageana  Pfeiffer 1836 (Mexican Pincushion Cactus)
Named for: Friedrich Adolph Haage de Erfurt (1796 - 1866) German botanist 
This is a solitary or occasionally clumping globose cactus. Old plants may produce basal offsets. The axils produce abundant wool. Tubercles have 16 - 18 fine white radial spines and 1 - 2 stout grey-brown straight central spines. Flowers are pink to magenta-pink with a darker midstripe, produced in a ring around the top of the plant.
 
Native to a wide range in the Mexican states of Veracruz, Puebla, México, Morelos, Oaxaca and Ciudad de México.

Mammillaria hahniana - Holly Gate Cactus Nursery reference collection

Mammillaria hahniana  Werdermann 1929 (Old Lady Cactus)
Named for: Adolf Hahn (b. 1954) German cactus collector from Berlin 
The axils of some clones produce white hairs up to 1.5 in long that cover the globose to cylindrical green plant body. Nurserymen tend to propagate extreme forms but this is unreprentative of the wild population. The areoles have 20 - 30 hair-like radial spines and 1 - 4 short white central spines with darker brown tips. Flowers are in shades of pink.
 
Native to the central Mexican states of Guanajuato, Querétaro Arteaga and Tamaulipas.
Photo: Holly Gate Cactus Nursery reference collection

Mammillaria heyderi - in fruit, Dog Canyon, Big Bend National Park, Texas.
Dog Canyon, Big Bend National Park, Texas.

Mammillaria heyderi  Muehlenpfordt 1848
Named for: Privy Councellor Eduard Heyder (1808-1884) German cactus expert from Berlin 

 
Native to Oklahoma, New Mexico and Texas USA and the Mexican states of Tamaulipas, Nuevo León, Coahuila, Durango, Sonora, San Luis Potosí and Veracruz.

Mammillaria heyderi var meiacantha - West of Terlingua, Texas.
West of Terlingua, Texas.
Mammillaria heyderi var meiacantha - in flower, Big Bend National Park, Texas.
Big Bend National Park, Texas.

Mammillaria heyderi subsp. meiacantha  (Engelmann) D.R. Hunt 1997

 

Mammillaria lasiacantha

Mammillaria lasiacantha  Engelmann 1856
Name: Greek lasios = hairy + akanthos = spine 
This mature Mammillaria lasiacantha is only about 1.5in in diameter. The plant body is entirely obscured by a lacy mat of white spines. Areoles produce 40 - 80 smooth to plumose radial spines held against the plant body and no central spines. Small cream flowers, whose petals have a green, yellow, pink to pale purple mid-stripe, are produced in late Winter to early Spring.
 
Native to Chihuahuan desert limestone soils in Texas and New Mexico and the Mexican states of Chihuahua, Coahuila, Durango, Nuevo León, San Luis Potosí, Sonora and Zacateca.
Photo: Limestone cliffs above and to the South of Terlingua.

Mammillaria longimamma

Mammillaria longimamma  A.P. de Candolle 1828
Syn. Dolichothele uberiformis  (Zuccarini) Britton & Rose 1923
Name: Latin longimamma = long nipple 
Thick taproots support a light green stem with long, soft tubercles. The main stem forms a clump by basal offsetting. Areoles produce 8 - 10 long pale brownish radial spines and a single long straight central spine. Flowers, produced from the axils, are yellow with a yellow stigma and relatively large and are followed by yellowish fruit.
 
Native to the Mexican states of Hidalgo and Querétaro. In cultivation a deep pot is advisable to accommodate the tap root and a very free-draining potting mix and careful watering are advisable. A single whole tubercle is sufficient to propagate this cactus.

Mammillaria microhelia

Mammillaria microhelia  Werdermann 1930
The short (6 in) cylindrical body is hidden by 30 -50 fine white radial spines with a pectinate arrangement and 1 - 4 brown central spines from each tubercle. Plants may be solitary or clump up by basal offsetting. Flowers are pale yellow or pink.
 
Native to a limited range in the Mexican state of Querétaro, growing among volcanic rocks. Easy in cultivation.

Mammillaria perezdelarosae

Mammillaria perezdelarosae  H. Bravo & L. Scheinvar 1985
Syn. Mammillaria bombycina ssp. perezdelarosae  (Bravo & Scheinvar) D.R. Hunt 1997
Named for: Jorge Perez de la Rosa (b. 1955) Mexican forestry specialist, Secretary of Botanical Institute of University of Guadalajara. 
This slow-growing solitary or clumping cactus has globose tuberculate stems, becoming cylindrical. The areoles produce 30 - 60 very fine white radial spines in a pectinate arrangement and 1 -2 reddish-brown, hooked central spines. Flowers are greenish white to pale pink with a darker mid-stripe, followed by red fruit containing dark brown seeds.
 
Native to the Mexican states of Jalisco and Aguascalientes.

Mammillaria pottsii

Mammillaria pottsii  

 
Native to
Photo: Limestone cliffs above and to South of Terlingua.

Mammillaria prolifera - cultivated

Mammillaria prolifera  (Miller) Haworth 1812 (Texas Nipple Cactus)

 
Widely distributed from Texas into the Mexican states of Coahuila, Nuevo León, Querétaro, San Luis Potosí & Tamaulipas. Also in Cuba, Dominican Republic & Haiti.
Photo: cultivated plant.

Mammillaria schiedeana

Mammillaria schiedeana  Ehrenberg 1838
This small cactus forms multiheaded clumps up to 2 in high. The globose to cylindrical stems are hidden by a mesh of pale yellow spines. Flowers are white to pale pink, sometimes with a darker mid-stripe and are followed by bright red cylindrical fruits. Roots are fleshy so need good drainage.
 
Native to the Mexican states of Hidalgo, Queretaro de Arteaga, San Luis Potosi and Tamaulipas. Likes a limestone soil.

Mammillaria surculosa

Mammillaria surculosa  Bödeker 1931
Syn. Dolichnthele surculosa   (Bödeker) Backeberg 1951
This dwarf globular dark-green cactus soon clumps up to form a mat. The areoles produce 15 radial white spines and 1 - 2 golden hooked central spines. There is a fleshy taproot. The small funnel-shaped yellow flowers are lightly perfumed and are followed by brownish fruit.
 
A rare plant, native to the Mexican states of San Luis Potosí and Tamaulipas growing at 9800 - 10500 ft above sea level. It is widely propagated in the horticultural trade.

Mammillaria varieaculeata

Mammillaria varieaculeata  Buchenau 1966
This cactus clumps up by dichotomous division of heads and also by basal offseting. Spine length is variable within the widl population. Axils produce 10 - 25 white bristles, 17 - 24 yellowish-brown radial spines and 1 - 5 darler brown central spines. The small flowers are red and are followed by scarlet club-shaped fruit.
 
Native to the southern part of the Mexican state of Puebla near its border with Oaxaca.

Mammillaria wiesingeri ssp. apamensis

Mammillaria wiesingeri ssp. apamensis  (W. Reppenhagen) D.R. Hunt 1997
These small globose cacti are solitary or clumping with age. Tubercles produce 13 - 16 yellowish radial spines and 1 - 2 darker central spines. Flowers are pink.
 
Native to the Mexican state of Hidalgo.

go to top  Matucana  Britton & Rose 1922
Named for: The town of Matucana in central Peru, capital of the province Huarochirí.  
The genus Matucana includes around 20 species of small globular or short cylindrical cacti with bright green stems and shallow tuberculate ribs. The showy funnel-shaped flowers with long floral tubes are often red but also pink, orange, yellow or white.
 
Native to the Andean highlands of central Peru above 8000 ft above sea level. These plants are sensitive to moisture and although some species tolerate light frost it is best to keep them at temperatures above 10°C during the Winter.
 
The genus Eomatucana Ritter has been merged into Matucana.

Matucana aureiflora

Matucana aureiflora  F. Ritter 1965
Syn. Borzicactus aureiflorus (Ritter) Donald 1971
Name: aureiflora = golden flowers 
This flattened globular cactus has a glossy green stem with pectinate spines supported by a tap root. The spination varies from a robust cage-like structure to very minimal spination allowing the sculptural form of the plant body to be appreciated. The areole of young plants produces a vestigial leaf scale. The golden-yellow flowers remain open day and night.
 
Native to Peru, growing in the valleys of the Andes around 9500 ft above sea level.

Matucana weberbaueri

Matucana weberbaueri  (Vaupel) Backeberg 1939
Syn. Cleistocactus sepium (Kunth) A.Weber 1904
Named for: August Weberbauer, Prussian (German) biologist 
A usually-solitary globular cactus whose areoles produce 25 - 30 long stright yellow-brown spines. Flowers are yellow to orange. In cultivation may offset with maturity.
 
Native to the Peruvian region of Amazonas, around 6800 ft above sea level.

Melocactus  Link & Otto (Turk's cap cactus)
Name: Latin Melus = melon + cactus 
The genus Melocactus includes about 40 species of cacti from the Caribbean, Mexico and South America. Juvenile plants have globose green bodies with 8 - 27 prominent ribs and stout spines. As these plants mature the main stem ceases growth and they develop a cephalium consisting of a dense mass of areoles with short spines at the apex of the plant. This structure may keep growing for years, in some species exceeding the size of the main body. The cephalium is often orange but may be white and produces many small, often pink flowers. Flowers are followed by waxy pink or red fruits like miniature candles.
 
Native to a range including the Caribbean Islands, Western Mexico, central America, Brazil to Southern Peru. In cultivation a Melocactus requires constant warmth to prevent marking or collapse.

Melocactus peruvianus - RBG Kew

Melocactus peruvianus  Vaupel 1913
Name: refers to presence of plant in Peru 

 
Native to Ecuador and Peru. Photographed at RBG Kew.

Melocactus zehntneri - RBG Kew Melocactus zehntneri - RBG Kew

Melocactus zehntneri  (Britton & Rose) Luetzelburg 1923
Named for: Leo Zehntner (1864 - 1961) Swiss entomologist & botanist 

 
Native to North-Eastern Brazil. Photographed at RBG Kew.

Myrtillocactus  (von Martius) Console 1897
Name: the fruits resemble those of Bilberry (Vaccinium myrtillus) 
The genus Myrtillocactus includes 4 species of shrubby, tree-like (25 ft) cacti with few (4-8) ribs and frequently-branching glaucous-green stems. Areoles may be without spines or have a single long, thick central spine with a few short, stout radial spines. Each areole can produce several greenish-white, waxy flowers less than 1 in long, and with short floral tubes. Flowers are followed by edible berries.
 
Native to Mexico including Baja California to Guatemala.

Myrtillocactus cochal - RBG Kew

Myrtillocactus cochal  (Orcutt) Britton & Rose 1909 (Candelabra Cactus)
Name: 'cochal' is the common name for this plant 
Myrtillocactus cochal grows as dense shrubs up to 12 ft tall with a short woody trunk bearing many six to eight-ribbed branches. Areoles have a long central spine with five shorter radial spines. The small flowers are greenish-white and followed by edible maroon berries.
 
Native to Baja California. Photographed at RBG Kew.

Myrtillocactus geometrizans - RBG Kew

Myrtillocactus geometrizans  (von Martius) Console 1897   (Bilberry Cactus, fruit = Garambullo)
Name: Latin geometricus = geometric, referring to the architectural stems 
The robust nature of Myrtillocactus geometrizans makes it suitable for grafting stock, although it is not cold-hardy. Each areole can produce several brownish buds that open into greenish-white, waxy flowers less than 1 in long, and with short floral tubes. Flowers are followed by edible, blue berries which are harvested for sale in Mexican markets.
 
Native to Mexico including Baja California to Guatemala and widely cultivated. A cristate form is commonly seen in cultivation. Photographed at RBG Kew.

Neolloydia  Britton & Rose 1923
Named for: Professor Francis Ernest Lloyd (1868 - 1947) British botanist who worked in America. 
This genus currently includes 2 species of cacti native to the dry Chihuahua Desert of Southern Texas and Northern Mexico. Several species have been transferred to Echinomastus.

Neolloydia intertexta  (Engelmann) L.D. Benson 1969   -   See Echinomastus intertextus

go to top  Oreocereus   (A.Berger) Riccob.
Name: Greek oros = mountain + Latin cereus = candle 
This genus includes 9 species of short columnar cacti with ribbed bodies that are covered in white hairs that are degenerate radial spines. Sharp central spines extend beyound the hairs. The tubular flowers are usually pink to red or orange.
 
Native to elevations of at least 10,000 ft in the Andes of Argentina, Bolivia, Chile, and Peru. The wooly covering doubtless protects against the harsh light and cold nights, but is probably also important for harvesting moisture from fogs that condenses on the hairs.

Oreocereus celsianus - cultivated Oreocereus celsianus - cultivated

Oreocereus celsianus  (Salm-Dyck) A.Berger ex Riccobono (Old Man of the Mountains)
Named for: Jacques Philippe Martin Cels (1740 - 1806) French botanist 
This columnar (10 ft) cactus has a body with 10 - 25 ribs, covered in white hairs through whic protrude sharp brown spines. Mature plants clump up by basal offsetting. The tubular red flowers are attractive to humming birds.
 
Native to Andes mountains of Argentina, Bolivia and Peru.

Oreocereus trollii - cultivated

Oreocereus trollii  Kupper 1929 (Old Man of the Mountain / Andes)
Syn. Borzicactus celsianus var. trollii (Kupper) G.D.Rowley 1986
Named for: Carl Troll (1899 - 1975) German botanist & geographer 
This short (2 ft) columnar cactus has a ribbed body that is densely coated in matted white hairs with protruding brown spines. Mature plants clump up by basal offsetting. The tubular flowers are violet-red to pink.
 
Native to Andes mountains of Northern Argentina and Southern Bolivia growing at elevations of up to 14,000 ft above sea level. Popular in cultivation but needs careful watering to avoid the white hairs wicking up salts and becoming dicoloured. Avoid watering during cold weather and Winter.

go to top  Pachycereus  (A. Berger) Britton & Rose 1909
Name: Greek pakhus = thick + Latin cereus = candle 
The are 9 - 12 species of Pachycereus, whose stout ribbed stems form columnar shrubs and very large tree-like cacti branching well above the ground to form a candelabra. Young growth is often fiercely spined, but mature growth above the reach of herbivores much less spiny. The large tubular flowers have a hairy or scaly brownish outer surface and white to pale pink interiors.
 
Native to Mexico, Baja California and the Southern edge of Arizona. Slow growing Pachycereus pringlei (Cardón) is fairly common in cultivation as an immature plant. Some species contain toxic, psychoactive alkaloids and may have been used in native ceremonies.

Pachycereus pringlei

Pachycereus pringlei  (S. Watson) Britton & Rose 1909 (Cardón, Mexican Giant Cardón)
Named for: Cyrus Guernsey Pringle (1838 - 1911) American botanist, explorer & plant breeder.
Common name: Cardón from the Spanish cardo = thistle
 
This is one of the largest cacti in the world, whose trunk with 11 - 17 ribs typically grows over 30ft tall and 3 - 4ft in diameter. Specimens have been recorded as growing 63ft tall during a lifespan of hundreds of years. Small specimens, typically seen in glass-house collections, are very spiny with 20 - 30 gray spines per areole but the spines are mostly lost as the trunk grows above the reach of herbivores. Mature specimens have side branches to the trunk forming a candelabra of branches. White flowers are produced in the Spring followd by tan coloured, spiny fruits.
 
Native to the Mexican states of Sonora and Baja California. Symbiotic nitrogen-fixing micro-organisms on the roots allow this cactus to grow without soil, even on bare rock. The spiny fruits contain edible pulp. This cactus produces alkaloids and a slice was traditionally used to treat rheumatism and aches.

Lophocereus schottii

Lophocereus  (A. Berger) Britton & Rose 1909
Plants in this genus have been transferred to Pachycereus.

Pachycereus schottii  D.R. Hunt 1987 (Senita Cactus)
Syn. Lophocereus schottii Britton & Rose 1909
Mature flowering stems develop a pseudocephalium of long, hairlike, grey spines towards their ends.
Photograph: Organ Pipe Monument Az.

go to top  Parodia  Spegazzini 1923
Named for: Lorenzo Raimundo Parodi, Argentine biologist 
The genus Parodia includes about 50 species of globular cacti, some of which elongate into short columnar plants. All species have deep ribs furnished with spines along their edge and usually single yellow or red flowers near the growing point, produced throughout the year.
 
Parodia are native to Argentina, Brazil, Colombia, Paraguay, Peru and Uruguay. The genus was expanded by transfer of species from the genera Eriocactus, Notocactus and Wigginsia. These free-flowering cacti are popular and easy to grow in a sunny place.

Notocactus  (K.M. Schumann) Frič 1928 Name: Greek = cactus of the south 
The 25 species from the obsolete genus Notocactus were moved into the genus Parodia in the 1980s but the name persists in books and plant labels. Notocacti have globose bodies elongating into short columns. The relatively large, funnel shaped flowers in yellows and red are produced throughout the year, each flower usually lasting several days.
 
Notocacti are native to lowlands of Argentina, Paraguay, Uruguay, and Southern Brazil.

Parodia magnifica - cultivated Parodia magnifica - cultivated

Parodia magnifica   (Ritter) F. H. Brandt 1982
The spherical to columnar blue-green plant body has dense yellow to brown spines and hairs along its ribs. Old plants clump up by offsetting. Pale yellow flowers are produced at the apex of the cactus.
 
Native to Southern Brazil, Paraguay, Uruguay and Argentina.
Photo: a very old clump at RBG Kew.

Parodia scopa - cultivated

Parodia scopa  (Sprengel) N. P. Taylor 1987
Syn. Notocactus scopa  (Sprengel) A. Berger 1929
Name: Latin scopa = broom, referring to the dense spines 
A globular cactus becoming cylindrical with age. The spiny, wooly crown produces yellow flowers in early Summer.
 
Native to Southern Brazil and Uruguay.

Notocactus succineus - cultivated

Notocactus succineus  F. Ritter 1970 (Silver Ball Cactus)
Syn. Parodia scopa subsp. succinea (F. Ritter) Hofacker & P.J. Braun 1998

 
go to top  Peniocereus  (A. Berger) Britton & Rose 1909 (Night-Blooming Cereus, Queen of the Night)
Name: Latin penis = tail + Latin cereus = candle  
The genus Peniocereus includes about 8 species of cacti from the South-Western USA and Mexico. A very large underground tuber supports long thin stems that scramble through other supporting bushes. Flowers typically open during the night.
Wilcoxia viperina

go to top  Wilcoxia  Britton & Rose 1909
Named for: Timothy E. Wilcox, US General  
Some species of Wilcoxia have been transferred to Peniocereus and the genus Wilcoxia
has been reduced to Echinocereus section Wilcoxia (Britton & Rose) N.P. Taylor.

Wilcoxia viperina
Syn. Peniocereus viperinus

go to top  Rebutia  K. Schumann 1895
Named for: Pierre Rebut (1827 - 1898) French vine grower, cactus collector & nursery owner. 
The genus Rebutia consists of small globular free-flowering cacti native to Boliva and Argentina. The bodies do not have ribs but regularly-arranged tubercles. Most species form clumps by offsetting from their base. The red, orange, yellow and white flowers are relatively large compared to the plant body and appear to be self-fertile, producing seed which may germinate around the plant.
 
Because of repeated splitting and lumping of genera, and transfer of some species into Lobivia / Echinopsis the number of species of Rebutia is indeterminate, but probably in the range 12 - 40 species. Species that were formerly in the genera Aylostera, Sulcorebutia, Weingartia and others have been lumped into Rebutia, so these often variable plants are seen with many synonyms.
 
These popular cacti are easy to grow and flower freely on a sunny window-ledge. Several hybrids are in circulation.

Rebutia albiflora

Rebutia albiflora  Ritter & Buining 1963
Named for: Latin albi = white + flora = flower 
This clumping cactus has small globose stems covered with soft radial spines. The relatively large (1 in diameter) flowers are white to pinkish-white with an externally pink flower tube and are followed by dry red fruits.
 
Native to South-East Bolivia.

Rebutia breviflora

Rebutia caineana  Cárdenas 1966
Syn. Rebutia breviflora  (Backeberg) D.R. Hunt 2002  Syn. Sulcorebutia breviflora Backeberg 1966
This globular cactus has a long, thick tuberous root and clumps up by basal offsetting. Yellow funnel-shaped flowers are produced freely on mature stems.
 
Native to Cochabamba, Potosi, Bolivia, where it grows among sandstone rocks at an altitude of 6500 - 9800 ft above sea level. The tap root requires careful watering or it may rot.

Rebutia fiebrigii Rebutia fiebrigii

Rebutia fiebrigii (Gurke) Britton & Rose ex. Bailey 1916
Syn. Rebutia albipilosa  F. Ritter 1963, Rebutia spinosissima
Named for: Latin albi = white + pilosa = spine 
A flattened-globose cactus densely-covered in soft, long white spines. The orange flowers are funnel-shaped on a long tube.
 
Native to Northern Argentina.

Rebutia heliosa x albiflora

Rebutia heliosa x albiflora
An attractive, free-flowering hybrid that quickly forms a mat of small, globular plant bodies. As with many hybrids, some variation is seen in the flower colours and selected forms have been propagated with flower colours from pale pink to peach.

Rebutia spegazzinia

Rebutia spegazziniana  Backeberg 1933
Syn. Rebutia tarijensis  Ritter 1977

Rebutia steinbachii

Rebutia steinbachii  Werderman 1931
Syn. Sulcorebutia steinbachii  (Werderman) Backeberg 1951

go to top  Rhipsalis  Gärtner 1788 (Mistletoe Cacti)
Name: Greek rhips = wickerwork, refering to slender, flexible stems. 
Rhipsalis is the largest genus of epiphytic cacti. The succulent photosynthetic stems may be cylindrical, angular of flattened and vary considerably in thickness. They usually branch frequently. R. pilocarpa is unique in having stems that are densely covered in areoles with bristles. In all other species, spines are absent or only on juvenile growth. Flowers are usually small and white, occasionally yellow and red in one species (R. hoelleri.)The fruits are white, pink, red or yellow berries.
 
With the exception of Rhipsalis baccifera all species are native solely to tropical rainforests of South America, especially Brazil, and to the Caribbean.

Rhipsalis baccifera (J.S. Mueller) Stearn 1939 (Mistletoe Cactus)
This is a variable species with a wider natural distribution than any other cactus. South American plants are diploid but those from Mesoamerica, the Caribbean and elsewhere are tetraploid. R. baccifera is found also in tropical rainforests of Africa, Madagascar, Seychelles, Mauritius, Reunion, India and Ceylon. As R. baccifera is not ancestral to Cactaceae and unlikely to have evolved before separation of the continents, this pandemic distribution may reflect transport by migratory birds or humans, perhaps for the sweet berries.

Rhipsalis baccifera ssp. mauritiana

Rhipsalis baccifera ssp. mauritiana  (De Candolle) Barthlott 1987 (Mistletoe Cactus)
This sub-species from the Indian Ocean area is tetraploid with 44 chromosomes. The white berries are edible and larger than those of the diploid sub-species.

Rhipsalis cereoides

Rhipsalis cereoides  (Backeberg & Voll) Backeberg 1937
This cactus grows mainly as an epiphyte. The three (occasionally four) -cornered stems are joined end to end, often branching at the sttem joints. Small areoles with a few bristles can be found along the stems. The small white flowers appear from the areoles in groups and are followed by red transluscent fruit.
 
Native to rainforests of Brazil.

Rhipsalis pilocarpa Rhipsalis pilocarpa

Rhipsalis pilocarpa   Lofgren 1903
Name: Latin pilus = hairy + carpus = fruit 
The long thin branching stems are distinctively covered in fine hairs growing from otherwise spineless areoles. In mid-Winter, bell-like white flowers are produced at the ends of the stems. The interiors of the flower tunes may be tinged with pink. Flowers are followed by red berries whose surface has areoles bearing tufts of hairs.
 
Native to Brazil. This is an ideal plant for a shady corner of the greenhouse or conservatory.

go to top  Schlumbergera  Lemaire 1858 (Christmas Cactus)
Named for: Frédéric Schlumberger (1823 - 1893) French cactus grower from Anthieux 
The genus Schlumbergera includes 6 species of epiphytic cacti from South-Eastern Brazil. The stems are formed from flattened, jointed segments that resemble fleshy leaves. Pink flowers arise from areoles at the stem joints and notched tips of the stems and are bird pollinated. Tiny vestigial spines can also be found in these places.
 
By selection and hybridization, plant breeders have produced many varieties with different forms and flower colours. Flowering is controlled by temperature and short day length.

Zygocactus truncatus

Zygocactus  Schumann 1890
The obsolete genus Zygocactus is included in Schlumbergera.

Schlumbergera truncata  (Haworth) Moran 1953
Syn. Zygocactus truncatus  (Haworth) K. Schumann 1890 (Christmas cactus)
The traditional "Christmas Cactus" is a hybrid Schlumbergera x buckleyi with a magenta flower. The wild form of Schlumbergera truncata in Brazil has a red flower. A range of hybrids with flowers in other colours have become available recently.

go to top  Sclerocactus  Britton & Rose 1922
Name: Greek sclero = hard referring to fruit + cactus  
The genus Sclerocactus includes about 15 species of particularly xerophytic cacti from North America. Plant bodies are globular to short columns with tuberculate ribs and dense spination. Most species have at least one hooked spine at each areole but a few species do not have hooks. Funnel-shaped flowers in shades of pink, yellow, and greenish are produced near to the growing point.
 
Native to the Southern USA and Northern Mexico.
The genera Ancistrocactus, Echinomastus, Glandulicactus and Toumeya are lumped into Sclerocactus by some authors.

Sclerocactus parviflorus Sclerocactus parviflorus

Sclerocactus parviflorus  Clover & Jotter 1941 (Devil's Claw Cactus)
Name: Latin parviflorus = small flowers, perhaps not entirely appropriate 

 
Extreme left: Robin Howard, Cheyenne Mountain State Park, Colorado. June 2008
Left: Robin Howard, Colorado Springs, Colorado. June 2008

Toumeya papyracantha - salt flats, Texas.

Toumeya  Britton & Rose 1922
Named for: James W. Toumey (1865 - 1932) Dean of School of Forestry, Yale University (1919 - 1922) 
The monotypic genus Toumeya was merged into Sclerocactus  Britton & Rose 1922.

Sclerocactus papyracanthus (Engelmann) N.P. Taylor 1987 (Paper-Spined Cactus)
Syn. Toumeya papyracantha  Britton & Rose 1922
 
Photograph: gypsum salt flats in front of Guadalupe Mountains, Texas.

Sclerocactus scheeri

Sclerocactus scheeri  (Salm-Dyck) N.P. Taylor 1987
Syn. Ancistrocactus scheeri (Rose) Britton & Rose 1923
Named for: Friedrich Scheer (1792 - 1868) German botanist and cactus enthusiast. 
A fleshy tuberous taproot supports a usually-solitary, large globular cactus. Areoles have 13 - 28 radial spines and 3 -4 hooked central spines. Juvenile plants have only radial spines. Flowers are bright green to yellowish in early Spring.
 
Native to Texas and the Mexican states of Nuevo León and Tamaulipas. Indians used the central spines as fish hooks.
Photo: Amistad Recreation Area, Texas.

Sclerocactus uncinatus Sclerocactus uncinatus

Sclerocactus uncinatus  (Galeotti) N.P. Taylor 1987 (Turk's Head Cactus)
Syn. Glandulicactus uncinatus  (Galeotti) Backeberg 1939

 
Photo: Black Gap Wildlife Management Area near Dog Canyon, Texas.

go to top  Selenicereus  (A. Berger) Britton & Rose 1909 (Moonlight Cacti)
Named for: Selene, Greek moon goddess + Latin cereus = candle, referring to nocturnal flowering  
The genus Selenicereus includes 28 species of climbing or scrambling epiphytic cacti with flat to angled stems producing aerial roots and often rooting where they touch a suitable substrate. Stems may be spiny or without spines. The funnel-shaped flowers are usually large, white, yellow to pink and very fragrant, tending to be nocturnal. Fruits are fleshy and covered with spines. Hylocereus megalanthus - Yellow Pitahaya
 
Native to rain forests of the Caribbean and central to South America.
Hylocereus megalanthus Syn. Selenicereus megalanthus (Yellow Pitahaya) widely cultivated commercially for its fruits, may be a hybrid between Hylocereus and Selenicereus.

Selenicereus anthonyanus

Selenicereus anthonyanus (Alexander) D.R. Hunt 1989 (Fish Bone Cactus)
Syn. Cryptocereus anthonyanus  Alexander 1950
Named for: Dr. Harold E. Anthony (1890 - 1970) American zoologist & paleontologist, first to flower this plant 
The notched stem may be an adaptation to the low light levels under the rainforest canopy, by increasing the area of the photosynthetic stem instead of producing leaves. The large fragrant flowers open for just one night.
 
Native to the rainforests of Chiapas, Oaxaca, Tabasco and Veracruz, Mexico.

Selenicereus grandiflorus

Selenicereus grandiflorus  (Linnaeus) Britton & Rose 1909 (Queen of the Night)
Name: grandiflorus = large flowered 
The large fragrant white flowers open for less than one night.
 
Native to Cuba, Cayman Islands, Jamaica, Haiti, Puerto Rico, Mexico, Belize, Guatemala, Honduras and Nicaragua.

go to top  Stenocactus  (Schumann) Berger 1929  Syn. Echinofossulocactus Britton & Rose 1922
Name: Greek steno = tight or narrow, referring to the ribs. 
This genus includes 11 species of mostly solitary, small globular cacti up to 4 in in diameter, with strong fin-like ribs and prominent spination. Small funnel-shaped flowers are produced near to the growing point of the plant and are often pale with a darker longitudinal stripe.
 
Native to the Chihuahuan desert of Mexico. Most Stenocactus grow easily and are free-flowering.
Echinofossulocactus is a synonym of Stenocactus.

Stenocactus crispatus - Holly Gate Cactus Nursery reference collection

Stenocactus crispatus  (de Candolle) A. Berger ex A. W. Hill 1933
Name: Latin crispus = with wavy margins, referring to the ribs. 

 
Widely distributed in the Mexican states of Guanajuato, Hidalgo, México Distrito Federal, México State, Oaxaca, Puebla, Querétaro, San Luis Potosí, Tamaulipas, Tlaxcala and Veracruz.
Photo: Holly Gate Cactus Nursery reference collection

Stenocactus multicostatus - Holly Gate Cactus Nursery reference collection

Stenocactus multicostatus  (Hildmann ex K. Schumann) A. Berger 1929
Syn. Echinofossulocactus multicostatus (Hildmann ex K. Schumann) Britton et Rose 1922

 
Native to the Mexican states of Aguascalientes, Coahuila, Durango, Guanajuato, Jalisco, Nuevo León, Querétaro, San Luis Potosí, Tamaulipas and Zacatecas.
Photo: Holly Gate Cactus Nursery reference collection

Stenocactus ochoterenianus

Stenocactus ochoterenianus  Tiegel 1933
Name commonly seen as S. ochoterenaus.
This solitary cactus has a dark green body with up to 30 undulating ribs and yellowish wool around the apex. Flowers are white to purple with a darker central stripe.
 
Native to the Mexican states of Hidalgo, Queretaro and Guanajuato.

Stenocactus vaupelianus

Stenocactus vaupelianus  (Werdermann) F. M. Knuth 1935
Syn. Echinofossulocactus vaupelianus  (Werdermann) H. C. Whitmore 1934
Named for: Friedrich Vaupel (1876 - 1927) German botanist 
This solitary species has a dark green body with around 35 undulate ribs. The body may be obscured by the strong spination, 10 - 25 radial and 1 - 4 central spines and white wool around the areoles. Flowers are pale yellow to pink, often with a darker mid-stripe.
 
Native to Mexian state of Hildago.

go to top  Stenocereus  (A. Berger) Riccobono 1909
Name: Greek steno = tight or narrow, referring to the ribs + cereus = candle 
The genus Stenocereus includes columnar cacti, often with multiple stems from their base or branching well above ground to form a tree-like structure. The cylindrical stems have multiple ribs, slightly indented at the areoles.
 
Members of the genus Stenocereus are found in Mexico including Baja California, Arizona, Colombia, Costa Rica, Guatemala, Venezuela and Caribbean Islands. A single species Stenocereus thurberi (Organ Pipe Cactus) can be seen at the South-Western edge of Arizona and has a National Monument named after it. Some species are cultivated for fruit similar to a dragon fruit. Plants that were formerly classified as Hertrichocereus and Lemaireocereus have been lumped into Stenocereus.

Stenocereus eruca

Stenocereus eruca  (Brandegee) Gibson & Horak 1978 (Creeping Devil)
Name: Latin eruca = caterpillar 
The Creeping Devil grows prostrate along the ground. It's 2in diameter spiny, cylindrical stem turns up a little at the growing point and roots where the body touches the ground. As the front of the plant grows, the rear end decays and crumbles away, so the effect is that the whole plant slowly moves forward. The stem branches near to the growing point. Eventually side branches detach and grow separately, as the decaying end reaches their branch point. The 4in long nocturnal flowers are pale yellow to pink followed by spiny fruit.
 
Native to sandy soils and coastal dunes in Baja California and Magdalena Island. This cactus is said to contain similar psychoactive alkaloids to peyote cactus and featured in native Indian ceremonies.

go to top  Thelocactus  (K. Schumann) Britton & Rose 1922
Name: Greek thele = wart or nipple + cactus  
The genus Thelocactus includes up to 15 species of small globular cacti with ribbed bodies, usually with angular tubercles. Areoles have up to 20 fine radiating spins with up to 6 stronger central spines which are sometimes hooked. These plants often have colourful spines in white, gray, yellow and reddish-brown. Funnel-shaped, relatively large white, yellow, red or magenta flowers are produced at the apex of the plant.
 
Native to Texas and Northern to central Mexico. Most species are solitary but some will clump up.
The genus Hamatocactus is now included in Thelocactus.

Thelocactus bicolor subsp. flavidispinus
Los Caballos, Brewster County, Texas
Thelocactus bicolor subsp. flavidispinus

Thelocactus bicolor (Galeotti ex Pfeiffer) Britton & Rose 1922
This solitary, globular cactus has 8 ribs bearing rounded tubercles. Areoles have glands and produce 8 - 18 yellowish to reddish radial spines and 3 - 4 central yellowish to reddish spines. Magenta flowers with a red throat are produced from Spring to Autumn.
 
Native to a wide range from Texas to the central Mexican state of San Luis Potosí, growing on limestone or sandstone soils. Numerous varieties have been named from different parts of the distribution.

Thelocactus bicolor subsp. flavidispinus  (Backeberg) N.P. Taylor 1998 (Glory of Texas)
Name: flavidispinus = yellow spined 
A globular to short columnar cactus with 13 ribs with tubercles,mostly obscured by dense straw-coloured to red spination. Areoles have 12 - 20 radial spines and 3 - 4 central spines. Short-lived, large magenta flowers are produced in late Spring.
 
Native to Big Bend Country, Texas into Mexico, growing on acidic soils. Not difficult in cultivation, but tends to grow taller than in its habitat.

Thelocactus bicolor subsp. flavidispinus
West of Terlingua, Texas
Thelocactus bicolor subsp. flavidispinus
author's plant  
Thelocactus conothelos

Thelocactus conothelos  (Regel & Klein bis) Backeberg & F.M. Knuth 1935
A globular cactus with four sub-species and a somewhat variable flower colour from white, yellow, red to purple.
 
Native to the Chihuahuan Desert in the Mexican states of Nuevo León, San Luis Potosí and Tamaulipas.

go to top  Weingartia  Werdermann 1937
Named for: Wilhelm Weingart (1856 - 1936), German amateur cactus expert and close friend of Werdermann 
Weingartia is a genus with 60 species of globular to shortly-cylindrical cacti with 12 - 18 tuberculate ribs arranged as a spiral. Yellow to orange funnel-shaped flowers are produced near to the growing point with up to 3 flowers per areole.
 
Native to the Andes of Southern Bolivia and North-West Argentina at elevations of up to 12,500 ft. Some authors have lumped Weingartia into Rebutia, with three-quarters of the species as synonyms of R. canigueralii and R. neocumingii, but this is still controversial.

Weingartia neocumingii var neocumingii

Weingartia neocumingii var neocumingii  Backeberg 1950
Syn. Rebutia neocumingii (Backeberg) D.R. Hunt 1987

 
Photos left and below: Some very old plants at Holly Gate Cactus Nursery reference collection.

Weingartia neocumingii var riograndensis
  var. riograndensis
Weingartia neocumingii var sucrensis
  var. sucrensis
Weingartia neocumingii var trollii
  var. trollii