Psoralea pinnata L.
Common names: fountain bush (Eng.); fonteinbos, bloukeur, penwortel (Afr.); umHlonishwa (Zulu)
SA Tree No: 226.11
Psoralea pinnata is an erect shrub or small tree which grows up to 4 m high, with blue, lilac and white pea-shaped flowers which bloom from October to December. The common names 'fountain bush' and 'fonteinbos' refer to the fact that it grows along streams and in wet places.
Two of the outstanding characteristics of this genus are its strong scent, and the resinous, dark or transparent dots which cover the leaves.
The leaves are compound and are composed of several pairs of leaflets and a terminal one. The leaflets are 50 mm long and 3 mm wide and are aromatic when crushed. The pea-flowers are borne at the ends of the branches or in the axils of the upper leaves. Although the flowers are seldom very showy, they are delicate and charming on the slender branches. White-eyes are often seen probing for insects attracted to the flowers.
Distribution and habitat
Psoralea pinnata is a fairly widespread species, growing from the Clanwilliam District south towards the Cape Peninsula and then eastwards and northwards through George and Knysna to the Eastern Cape, KwaZulu-Natal, Swaziland and Mpumalanga.
There are 130 species worldwide with 50 species occurring in southern Africa.
Derivation of name and historical aspects
Psoralea pinnata is one of the earliest South African plants to have been cultivated. In 1690 it was growing in England from seed collected in the Cape.
The genus name Psoralea is based on the Greek word 'psoraleos' meaning warty or scurfy, in reference to the dots or warts on the bark. (The "P" in Psoralea is silent and the name is pronounced as if it begins with "s".)
The specific name pinnata (Latin) refers to the pinnate leaves. Another distinctive characteristic is that there is only one seed in a pod.
Growing Psoralea pinnata
As with most Fabaceae, growing Psoralea pinnata is quite difficult from cuttings. It is best grown from seed. A handful of soil taken from below the parent plant and added to the seed tray is generally helpful when sowing Fabaceae seeds. This helps to ensure that the symbiotic mycorrhiza which grow on the roots and encourage nutrient uptake are present.
Seedlings should be planted along a stream or in an area which receives a substantial amount of water.
Herbarium records show that it will even persist under pines and wattles. It would seem that it can successfully compete with established trees in difficult wet areas.
- PALMER, E. & PITMAN, N. 1972. Trees of southern Africa. Balkema, Cape Town.
- GOLDBLATT, P. & MANNING, J. 2000. Cape plants. A conspectus of the Cape flora of South Africa. Strelitzia 9. National Botanical Institute, Cape Town & Missouri Botanic Garden.
- COATES PALGRAVE, K. 1983. Trees of southern Africa, revised edn 2. Struik, Cape Town. Berenice Carolus Harold Porter National Botanical Garden November 2002
Harold Porter National Botanical Garden
Plant Type: Tree
SA Distribution: Eastern Cape, KwaZulu-Natal, Western Cape
Soil type: Sandy, Loam
Flowering season: Early Summer, Autumn
Flower colour: Purple
Aspect: Full Sun
Gardening skill: Easy