The tree wisteria is certainly one of the most spectacular of our
indigenous trees when in flower, mimicking the splendour of the
jacaranda, which unfortunately is proving to be an invader species
in parts of South Africa. Given time and effort this tree could
replace the jacaranda trees from Argentina and carpet Pretoria streets
with indigenous purple blooms instead.
decorative, small to medium-sized tree is deciduous, dropping its
leaves only for a short period in early spring. The tree is normally
multi-stemmed, but it can be pruned to form a single stem. The bark
of the stem is brownish grey, rough and deeply fissured. Leaves,
which are spirally arranged, are suspended from drooping branches.
drooping, blue-mauve, fragrant, pea-like flowers hang from the branches
in bunches, often covering the whole tree. Flowering time is from
August to January (spring and early summer). Flowers are followed
by papery, brown fruit pods, that hang from the branches in clusters,
and never split to release their seeds. Being a protected tree in
South Africa, wild specimens may not be removed, cut down or damaged.
Bolusanthus speciosus is widespread in wooded grasslands
in southern Africa, from Angola and Zambia down to KwaZulu-Natal.
Bolusanthus honours Harry Bolus (1834 to 1911), who was a
South African botanist and founder of the Cape Town Bolus Herbarium;
speciosus means beautiful or showy in Latin.
Animals including monkeys, gemsbok, giraffe and grey duiker eat
the pods and leaves.
Uses and economic value
The wood, which is highly sought after by carpenters, makes excellent
furniture. It works well on a lathe, turning out beautiful lampshades
and other articles. The straight growing stems are very hard, termite
resistant and used for fencing posts. The roots are used medicinally
to alleviate stomach problems and the inner bark used to treat abdominal
cramps. It also has excellent potential as a tree for landscaping
and growing in the home garden.
Growing Bolusanthus speciosus
alongside a group of Bauhinia galpinii with striking red
flowers, Bolusanthus speciosus is a sight to behold. It is
an ideal tree to grace a medium to small garden, as it never grows
too big. It can be grown in a container and looks spectacular on
any sunny patio. As mentioned earlier, the tree wisteria makes a
beautiful street tree with its non-invasive root system.
To propagate place the seeds in hot water and soak overnight. Sow
the seeds in containers filled with river sand, covering lightly
with finer sand. Remember that the sowing depth should not be deeper
than the diameter of the seed. The seeds germinate quickly and can
be transplanted after the second leaf has emerged. A good soil mixture
would be equal parts of river sand, loam and compost. With good
care this tree can grow up to 800 mm per year.
Bolusanthus speciosus can withstand moderate frost, but
will need protection for the first few years. It can also survive
periods of drought.
- GERMISHUIZEN, G. & FABIAN, A. 1997. Wildflowers of northern
South Africa. Fernwood Press, Vlaeberg, Cape Town.
- POOLEY, E. 1993. The complete field guide to trees of Natal,
Zululand and Transkei. Natal Flora Publications Trust, Durban.
- SCHMIDT, E., LOTTER, M. & McCLELAND, W. 2002. Trees and shrubs
of Mpumalanga and Kruger National Park. Redhotmoondog Communications & Jacana, Johannesburg.
- VENTER, F. & VENTER, J-A. 1996. Making the most of indigenous
trees. Briza Publications, Pretoria.
Pretoria National Botanical Garden