Calodendrum capense, beautiful tree from the Cape, the name
says it all (kalos means beautiful, and dendron tree
in Greek, capense is Latin for from the Cape), it is not
only a tree of the Cape, but also a tree of Africa. It occurs along
the south and east coast of southern Africa from around Swellendam
in the Western Cape through the Eastern Cape, KwaZulu-Natal, Mpumalanga,
Swaziland, Gauteng, North West and Northern Province and into tropical
Africa as far north as Tanzania and Ethiopia, and grows mainly in
forests and kloofs (ravines / gorges), but occasionally in scrub
and riverine bush, from sea-level to 2000 m. When in bloom, the
whole canopy turns pink. It is a magnificent sight.
In a forest environment, this tree can reach heights of up to 20
m, but at the forest margin or in the open it is shorter, approx.
7 m, with a more spreading canopy. In general this is a handsome
well-shaped tree with a single trunk and a dense rounded canopy.
trunk is smooth and an attractive mottled streaky grey, buttressed
and lichen-covered in older specimens. The leaves are dark green,
relatively large (5-22 cm long x 2-10 cm wide), simple, with untoothed
undulate margins, and elliptic in shape. At the coast this tree
is often evergreen, but inland it is deciduous with rich yellow
autumn colours. The flowers are large and striking, faintly sweet-scented
and carried in conspicuous terminal panicles during early summer
(October to December). Close up, each delicate flower has five long
narrow pale pink petals (4-5 cm x 0.5 cm), alternating with five
petal-like staminodes (sterile stamens), also pale pink but conspicuously
dotted with purplish to maroon glands. The calyx is star-shaped
and persists after the flower has dropped off. The
ovary, on a long gynophore (stalk carrying the female organs), swells
to form the fruit which is green maturing to brown, 5-lobed woody
capsule with a rough warty surface, splitting during late summer
to autumn, to drop the large smooth black seeds which are hard but
surprisingly light in weight.
Birds do not find the nectar-filled flowers inviting, but butterflies
do feed on them. Samango and vervet monkeys, and rameron and olive
pigeons, cinnamon doves and Cape parrots eat the seeds. The larvae
of several butterfly species, including the orange dog (Papilio
demodocus) which also uses other citrus family trees, breed
on the foliage.
The timber is white or light yellow, fairly hard but bends well
and is easily worked. It is used for tent bows, wagon-making, yokes,
planking, shovel handles, and furniture, and is considered one of
the most generally useful hard woods. The bark is used as an ingredient
of skin ointments and is sold at traditional medicine markets. Seeds
are crushed and boiled to obtain oil that is suitable for making
soap. The Xhosa believe that the seeds have magic properties, and
hunters used to tie them around their wrists when hunting to bring
them skill and good luck.
Calodendrum capense got its common name because William
Burchell (1782-1863) thought that the flower and fruit resembled
the horse chestnut. It is, however, not closely related to the chestnuts,
Castanea species, which belong in the Fagaceae, the beech
& oak family. And Carl Peter Thunberg (1743-1828), pupil of
Linnaeus and the 'father of South African botany', was so excited
at the sight of a tree in flower when he visited Grootvaderbosch
in 1772, that he fired his gun at the branches until one broke and
delivered the blooms into his hand. He was the one who named it
Calodendrum capense is a member of the Rutaceae, the buchu
& citrus family, a family of ±160 genera and ±1650
species that occur in warm temperate regions of the world, with
22 genera and 290 species in southern Africa. One of the diagnostic
features of this family is the presence of oil glands on the leaves,
visible as tiny translucent dots when held up to the light. Another
common feature, caused by the oil, is the strong scent of the leaves,
particularly when they are crushed. Related tree genera in southern
Africa include, Clausena, Vepris, Oricia, Citropsis, Zanthoxylum
(=Fagara), Toddaliopsis, and Teclea. Well-known
shrubby relatives include the buchus Agathosma species, and
the confetti bushes Coleonema species.
Growing Calodendrum capense
Calodendrum capense is a very ornamental tree, suitable
for use as a shade or specimen tree in gardens and parks, also as
a street tree. It does best in deep fertile, well-composted soil
with plenty of moisture, particularly during spring and summer,
and requires a warm sunny position. To develop and maintain its
shapely canopy, it requires protection from strong, sustained winds,
like Cape Town's south-easter. Young plants require protection from
frost, but established specimens should be able to survive in Zone
9 (-7°C / 20°F) When grown in bitterly cold areas, it is likely not
to flower very well.
Calodendrum capense is propagated by seed or cuttings. Seed can
be sown as soon as it drops in late summer to autumn, or kept refrigerated
and sown the following spring or summer. Sow in deep trays in well-drained
soil. Germination should take 10-40 days but may be erratic with
older seed. In colder climates, bottom heat should be used. This
tree has a relatively long juvenile phase and will rarely flower
until it is 7 or 8 years old.
Cuttings should be taken from new growth in spring to early summer,
treated with a rooting hormone and rooted under mist using bottom
heat. Trees propagated by cuttings should flower in 4 to 5 years.
Young trees transplant easily and under ideal conditions can grow
nearly 1 m in a year.
- Palmer, E. and Pitman, N., 1972, Trees of Southern Africa, A.A.
Balkema, Cape Town
- Coates Palgrave, Keith, 1977, Trees of Southern Africa, First
Edition, C. Struik Publishers, Cape Town, Johannesburg.
- Venter, Fanie & Julye-Ann, The Cape Chestnut, Farmers Weekly
June 10, 2020.
- Leistner, O.A. (ed.), 2000, Seed plants of southern Africa:
families and genera, Strelitzia 10., National Botanical Institute,
Author: Alice Notten