The Succulent Plant Page goes to Families of Succulent Plants goes to

The Geranium Page
Geraniaceae

Search this site:        
Botanical BookmarksBotanical Glossary SITEMAP Email: webmaster

Geraniaceae   -   Geranium Family

The Geraniaceae is a widely-distributed family of herbs with 7 genera containing around 800 species, often with hairy stems and cleft or compound leaves containing aromatic oils. Flowers generally have 5 sepals, 5 petals, 5 - 10 stamens and 5 fused carpels that separate when fruiting. Species currently in the genera Pelargonium and Erodium were originally included in the genus Geranium by Linnaeus, but were separated into separate genera by Charles L'Héritier (1789). However, "Geranium" has persisted in the horticultural world as a popular name for Pelargoniums. Geraniaceae are widely cultivated for their horticultural merit and considerable effort has been put into producing a wide range of colours and leaf and flower forms.
 
The genus Erodium (Storksbills) (60 species) has symmetrical flowers with 5 stamens. They include small hardy alpine plants suitable for rockeries. Some species develop bonsail-like woody stems.
 
The genus Geranium (Cranesbills) (422 species) has symmetrical flowers with 10 stamens. Geraniums are found in temperate and sub-tropical regions especially the Eastern Mediterranean and include many hardy garden plants. The common name refers to the shape of the seedpods.
 
Pelargoniums (280 species) have asymmetrical flowers with 7 stamens. Choice succulent and caudiciform Geraniaceae are found in the genera Pelargonium and Monsonia (Sarcocaulon), with both summer and winter growers. Monsonia flowers have 15 stamens.

Geranium
Above: The hairy stems of English native Geranium robertianum "Herb Robert" are surprisingly succulent.
Pelargonium cotyledon seed pod
Above: Pelargonium cotyledonis
stork's bill seed pod
 

Pelargonium  L'Héritier 1789
Name: Greek pelargos = stork, referring to the seed pods that resemble stork's bill's.
A large genus of 280 species of which the majority are native to South Africa. They are popular undemanding flowering plants ranging from non-succulent herbs to shrubby plants with fleshy leaves, stems and roots or tubers that may be of interest to collectors of caudiciform plants. The stems of a few species are armoured with spines. In many species leaves and stems are pubescent. Leaves are usually alternate and either palmately lobed or pinnate, often with long petioles. The leaf surface may be patterned with light or dark zones. The five-petalled flowers are asymmetrical and most colours can be found among the various species.
 
Pelargoniums are important ornamental plants, although the horticultural trade focuses on mainly non-succulent cultivars, with a limited genetic base representing just a handful of the wild species. Numerous cultivars and hybrids are available in a wide range of colours including shades of purple, maroon, red, pink and white and variegated petals. Yellow(ish) flowers are a recent development in horticultural varieties although present in several species e.g P. gibbosum.
 
Many species of Pelargonium, especially P. graveolens, produce aromatic oils with aromas including rose, mint, citrus, apple and nutmeg. The most commercially important cultivars are rose scented. P. graveolens is cultivated on a large scale as a source of essential oils.
Succulent Pelargoniums should be potted up in a free-draining compost which should be allowed to dry out between waterings. Pelargoniums can be propagated from stem cuttings, which should be cut just below a leaf joint, from where the new roots will form.

Pelargonium  bowkeri

Pelargonium bowkeri  Harvey 1862
A geophytic species with a mass of pinnate feathery leaves growing from a large underground tuber. The inflorescence is a cluster of light yellow-green flowers held close to the leaves.
 
Native to the Eastern Cape of South Africa.

Pelargonium carnosum

Pelargonium carnosum  L'Héritier 1789
A variable, shrubby plant with thick, waxy yellow-green stems up to 4 ft tall and a thickened root. The bipinnate leaves are crisped to a variable extent and produced in tufts from growing points along the stem. The inflorescence is a cluster of white flowers with bright pink style and stamens with orange pollen.
 
Native to the North-Western Cape of South Africa.

Pelargonium carnosum
Pelargonium cotyledon Pelargonium cotyledon

Pelargonium cotyledonis  L'Héritier 1789 (Old Father Live For Ever)
A shrubby plant with few thickened, succulent branches. The simple, heavily veined leaves are deciduous during the Summer and produced around the growing tips of the stems. The inflorescence is a cluster of relatively large white flowers on a long stalk, with white style, stamens and pollen.
Native to the island of St. Helena.

Pelargonium crithmifolium Pelargonium crithmifolium

Pelargonium crithmifolium  J.E. Smith 1793
A shrubby plant with thick knobbly stems to about 2 ft tall. The bipinnate leaves are succulent and produced in tufts at growing points on the stem. The inflorescence is a cluster of white flowers with pink markings on the base of the upper pair of petals, a red style and stamens with yellow pollen.
Native to an wide area from Namibia to the North-Western Cape.

Pelargonium gibbosum Pelargonium gibbosum

Pelargonium gibbosum  L'Héritier 1789
A sprawling sub-shrub with thickened stems producing a mass of annual growth with glaucous semi-succulent pinnate leaves. The inflorescence is a panicle of yellow flowers, contrasting with the foliage.
Native to the coastal Western Cape of South Africa.

Pelargonium grandicalcaratum Pelargonium grandicalcaratum

Pelargonium grandicalcaratum  Knuth 1918
A woody shrub whose stems bear succulent pinnate leaves. Persistent petioles along the stems give the appearance of spines. The foliage is delightfully aromatic, somewhat reminiscent of the herb Thyme. The small flowers are white to pale yellow with fine red markings on the upper petals.
 
Native to Namibia and the North-Western Cape of South Africa.

Pelargonium paniculatum

Pelargonium paniculatum  Jacquin 1797
An infrequently-branching shrub with a thick 3ft trunk patterned with persistent petioles and bearing a head of pinnate succulent leaves. Leaves are deciduous during the Summer. The inflorescence is a panicle of small white flowers with pink markings on the base of the upper pair of petals, a white style and stamens with orange pollen.
 
Native to Southern Namibia.

Pelargonium paniculatum
Pelargonium tetragonum

Pelargonium tetragonum  L'Héritier 1789
A scrambling plant with branching three or four-angled stems producing non-succulent deciduous leaves at the stem joints. Leaves may have zonal markings and a degree of pubescence. The inflorescence is a cluster of pink flowers the upper petal of which has red markings.
 
Native to the South African Cape. This is one of the few species with succulent stems that is widely available in the horticultural trade although the foliage is not aromatic.

Monsonia  Linneaeus 1767 (Bushman Candles)
Named for: Lady Anne Monson, great-grand-daughter of Charles II
A group of erect, woody sub-shrubs, some with a degree of stem or root succulence, waxy bark and spines. Monsonia has absorbed the former caudiciform genus Sarcocaulon. The waxy bark and resinous exudates of some former Sarcocaulons makes them inflammable even when the stems are green, explaining their common name.
 
Monsonias are native to areas of intense heat and aridity and need strong sunlight and careful watering to survive. Caudiciform Monsonias should be watered when in active growth and very sparingly, or occasionally misted to prevent dehydration, when dormant.

Monsonia

Monsonia (patersonii)
Spiny-stemmed Monsonia, North Escarpment, Nieuwoudtville. This species has small pink flowers, one of which can just be seen in the photograph. The wicked spines are a deterrent to herbivores in this arid environment.