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Cactaceae

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

The 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 the New World distribution is that of the epiphyte Rhipsalis baccifera which is distributed in Africa, Madagascar and Sri Lanka as well as in America. Most species of Cactaceae are spiny stem succulents, although there are a few woody shrubs (Pereskia) and more or less succulent epiphytes. The family contains numerous genera, which seem to be constantly under revision.
 
The Cactaceae are distinguished by modified buds that have become transformed into specialised areoles from which grow multiple spines and glochids (top right). These should be distinguished from solitary spines or thorns, sometimes branching above the plant body, on other plants e.g. spiny Euphorbias. In some 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. Fruit 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 spines.
 
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 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 characteristic.
 
Several species are cultivated for their juicy fruit (e.g. Opuntia ficus-indica, Selenocereus sp., Hylocereus sp.) and through introduction Cactaceae, especially Opuntia are found throughout the tropics. In some places cacti have become invasive weeds.
 
Many species of cacti are cultivated as ornamentals and 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 has been destroyed. 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. However, as there is little evidence of cacti in the fossil record, this logical sequence is based mainly on morphology. Recent DNA studies support the general groupings, but suggest some taxonomic rearrangements of species. Cacti generally have 22 chromosomes.



 

Summary of Cactaceae

  • Subfamily Pereskioideae: broad leaves, no glochids.
    Pereskia, Maihuenia
    (or Maihuenia may be separated into Subfamily Maihuenioideae.)
     
  • Subfamily Opuntioideae: fleshy round leaves present or absent, glochids present.
    Austrocylindropuntia, Brasiliopuntia, Cylindropuntia, Cumulopuntia, Grusonia, Micropuntia, Opuntia, Pereskiopsis, Pterocactus, Quiabentia, Tacinga, Tephrocactus, Tunilla.
     
  • Subfamily Cactoideae: no leaves*, no glochids.
    Ariocarpus, Astrophytum, Aztekium, Carnegiea, Cereus, Cleistocactus, Coryphantha, Echinocactus, Echinocereus, Echinomastus, Epithelantha, Escobaria, Ferocactus, Geohintonia, Hylocereus, Leuchtenbergia, Lobivia, Lophophora, Mammillaria, Matucana, Neolloydia, Obregonia, Parodia, Pelecyphora, Pilosocereus, Pediocactus, Rebutia, Rhipsalis, Sclerocactus, Schlumbergia, Stenocactus, Strombocactus, Thelocactus, Trichocereus, Turbinocarpus, Uebelmannia and all other genera.
     
    *Except that some species have seed leaves.
     
 
 
spine cluster
 
spine cluster
 
spine cluster
 
Examples of
cactus spine clusters
 
go to top  Subfamily Pereskioideae
 
Maihuenia poeppigii - RBG Kew

Maihuenia poeppigii - RBG Kew

Pereskia grandiflora - RBG Kew

Pereskia grandiflora - RBG Kew

 
go to top  Subfamily Opuntioideae
 
Opuntia engelmannii

Opuntia erinacea var. hystricina - near Salt Flats, Tx

Opuntia engelmannii

Opuntia engelmannii - near Marathon, Tx

Opuntia microsphaericus

Opuntia microsphaericus - Holly Gate Cactus Nursery reference collection

Opuntia sp.

Opuntia sp. - Holly Gate Cactus Nursery reference collection

 
go to top  Subfamily: Cactoideae
 
Ariocarpus
Ariocarpus fissuratus

Ariocarpus fissuratus - Big Bend National Park, Texas - in bud

Ariocarpus fissuratus

Ariocarpus fissuratus - Big Bend National Park, Texas - in bud

Ariocarpus retusus

Ariocarpus retusus - cultivated, flower

Ariocarpus scapharostrus

Ariocarpus scapharostrus - cultivated, flower


Astrophytum
Astrophytum myriostigma

Astrophytum myriostigma - (Turk's Head Cactus) - cultivated, Photo: Benno Stander 2014


Copiapoa
Copiapoa barquitensis

Copiapoa barquitensis - Holly Gate Cactus Nursery reference collection


Dactylifera
Dactylifera sp., - Holly Gate Cactus Nursery reference collection

Dactylifera sp., - Holly Gate Cactus Nursery reference collection


Echinocactus
Echinocactus grusonii seedlings

Echinocactus grusonii - seedlings

Echinocactus horizonthalonius - Maverick Mountain, Tx.

Echinocactus horizonthalonius - Maverick Mountain, Tx.

Echinocactus polycephalus -  Death Valley Ca.

Echinocactus polycephalus - Death Valley Ca.

Echinocereus
Echinocereus berlandii, - Holly Gate Cactus Nursery reference collection
Echinocereus engelmannii, - Holly Gate Cactus Nursery reference collection
Echinocereus enneacanthus - Big Bend National Park
Echinocereus lauii - cultivated, flower
Echinocereus lloydii - N. of Marathon Tx.
Echinocereus stramineus - Dog Canyon, Big Bend National Park

Escobaria
Escobaria tuberculosa, - West of Terlingua
Escobaria tuberculosa, - Dog Canyon, Big Bend National Park
Escobaria tuberculosa - cultivated
Escobaria strobiliformis seedlings

Gymnocalycium
Gymnocalycium aichrasense, - Holly Gate Cactus Nursery reference collection
Gymnocalycium friedrichii
Gymnocalycium lafeldense = bruchii - cultivated, flower

Lobivia wrightiana - cultivated, flower
Lophocereus schottii, - Organ Pipe Monument Az.
Lophophora williamsii, - West of Terlingua

Mammillaria
Mammillaria bocasana (yellow flower) - cultivated
Mammillaria bocasana (pink flower) - Holly Gate Cactus Nursery reference collection
Mammillaria glassii - cultivated, flower
Mammillaria gracilis - cultivated, flower
Mammillaria grusonii, - Holly Gate Cactus Nursery reference collection
Mammillaria hahniana, - Holly Gate Cactus Nursery reference collection
Mammillaria heyderi - in fruit, Dog Canyon, Big Bend National Park
Mammillaria heyderi var meiacantha, - West of Terlingua
Mammillaria microhelia - cultivated, flower
Mammillaria prolifera - cultivated, flower

Mediolobivia eos var. roseiflora - cultivated, flower
Morangaya pensilis, - Holly Gate Cactus Nursery reference collection
Notocactus succineus - cultivated, flower

Rebutia
Rebutia albiflora - cultivated, flower
Rebutia heliosa x albiflora - cultivated, flower

Rhipsalis pilocarpa - cultivated
Selenicereus anthonyanus - cultivated
Stenocactus crispatus, - Holly Gate Cactus Nursery reference collection
Stenocactus multicostatus, - Holly Gate Cactus Nursery reference collection
Thelocactus bicolor var flavidispinus - cultivated, flower
Thelocactus bicolor, - West of Terlingua
Toumeya papyracantha, - Salt Flats

Weingartia
Weingartia neocummingii var neocummingii, - Holly Gate Cactus Nursery reference collection
Weingartia neocummingii var riograndensis, - Holly Gate Cactus Nursery reference collection
Weingartia neocummingii var sucrensis, - Holly Gate Cactus Nursery reference collection
Weingartia neocummingii var trollii, - Holly Gate Cactus Nursery reference collection

Wilcoxia viperina - cultivated, flower
Zygocactus truncatus (probably a hybrid) - cultivated, flower