
Evergreen shrub with white flowers that stand out against the green forests and fill the air with a strong violet scent.
Description
Baphia racemosa is an evergreen shrub or small to medium-sized tree up to 10 m tall with a dense and somewhat round crown. Main stem straight, either broad or much branched. Bark smooth and grey on young branches, becoming rough and brown with age. Leaves alternate, simple, tapering at both ends, about 20–120 mm long and 10–80 mm broad. Leaf blade smooth, dark green above, slightly velvety below, with a wavy margin. Leaf stalk thickening at both ends.
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Baphia racemosa bark |
Baphia racemosa flowers |
Flowers produced in axillary racemes at ends of branches, about 60 mm long, pea flower-shaped, white with a golden yellow, ultraviolet-sensitive spot (honey-guide) on the upper petal, strongly violet-scented. All flowers open together. Appearing from August to January. Fruits flat, brown to black pods splitting, ± 100 mm long. They have an explosive mechanism which aids in seed dispersal.
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Baphia racemosa seed pod |
Baphia racemosa leaves |
Conservation status
Baphia racemosa is listed in the Red List of South African plants (Raimondo et al. 2009) as Least Concern.
Distribution and habitat
Baphia is a genus of about 80 species; 45 of these are confined mainly to the tropics and subtropics of Africa, extending to KwaZulu-Natal Province of South Africa and to the lowland forest areas of western Madagascar. Thirty-one of the 45 African tropical species occur at an altitude of 1000 m or below. The remaining 14 species have a wide altitudinal range of 0–1800 m.
South Africa is home to two species of Baphia, namely B. racemosa and B. massaiensis subsp. obovata var. obovata.
Baphia racemosa occurs in two provinces of South Africa. It is found along the coastal belt from Eastern Cape to the coastal forests of KwaZulu-Natal, extending up to the border of Mozambique and Swaziland. B. massaiensis is widely distributed from East Africa toZimbabwe, Namibia and Botswana. Within South Africa it is restricted to a small area in the northeast of Limpopo.
B. racemosa is found in coastal swamps, riverine forests, areas of secondary regrowth, lowland areas and forest-savanna habitats.
Derivation of name and historical aspects
The name Baphia is a Greek word which means dye, referring to the red dye made from the heartwood of a tropical African species, and racemosa refers to the racemose flower arrangement.
Ecology
Baphia racemosa is sensitive to frost but it can withstand short spells of drought. It occurs at low altitude, from 0–1000 m in coastal areas, on sandy or loam soils. Plants are usually found in riverine scrub and evergreen forest margins; they can reach 10 m in height, usually along streams and rivers.
The ripe pods burst with a very audible crack during dry weather to release the seeds. The sweet-scented flowers attract bees.
Uses and cultural aspects
Baphia racemosa has economic value. The plant is used as a street tree in coastal areas. The wood is used to make fighting sticks, hoe handles, boats and for pillars and beams in native huts. It was also used in building wagon frames. The leaves are a source of food for larvae of the blue-spotted charaxes, and the brown and orange-barred playboy butterflies. Parrots feed on young seeds.
Growing Baphia racemosa
This is a slow-growing plant which makes a beautiful display when planted in a group on the lawn. It has a moderate growth rate of 500–600 mm per year.
The plant is easily propagated from seed which should be collected before the pods split open. The seeds must first be soaked in hot water, left overnight and planted the next morning in a container filled with river sand. Seeds usually germinate in five to eight days after being sown. The plant should be sown in good fertile soil that contains plenty of compost and is watered regularly.
The tree is ideal for the small garden. Violet pea can withstand some drought, and older trees do cope with the odd frost but young plants need to be protected during germination and early growth.
References and further reading
- Joffe, P. 2001. Creative gardening with indigenous plants. A South African guide. edn 1. Briza Publications, Pretoria.
- Leistner, O.A. 2005. Seed plants of southern tropical Africa : families and genera., Southern African Botanical Diversity Network Report No. 26. SABONET, Pretoria.
- Pooley, E. 2003. The complete field guide to trees of Natal, Zululand & Transkei. edn 4. Natal Flora Publications Trust, Durban.
- Soladoye, M.O. 1985. A revision of Baphia (Leguminosae-Papilionoideae). Kew Bulletin 40: 291–386.
- Van Wyk, A.E.(Braam) & Van Wyk, P. 1997. Field guide to trees of southern Africa. edn 1. Struik, Cape Town.
- Venter, S.. & Venter, J. 1996. Making the most of indigenous trees,.edn 1. Briza Publications, Pretoria.
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Sifiso Mnxati
KwaZulu-Natal Herbarium
October 2010
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