
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 "P"
in Psoralea is silent and the name is pronounced as if
it began with the "s". The common names fountain bush
or 'fonteinbos' refer to the fact that it grows along streams
and in wet places. There are 130 species worldwide with 50 species
occurring in southern Africa.
Description
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 after
insects attracted to the flowers.
Distribution
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 Mphumalanga.
Derivation of name and historical aspects
One of the outstanding characteristics of this genus is its strong
scent, and the resinous, dark or transparent dots which cover
the leaves. 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 specific name pinnata (Latin)
refers to the pinnate leaves. Another distinctive characteristic
is that there is only one seed in a pod.
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.
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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.
References