Zeuxine africana, listed as Endangered on the South African Red List, is only known from a single locality—the busiest port of Southern Africa, Durban harbour. This area was bulldozed, not more than 8 years ago. This indicates that Z. africana is an opportunistic species that colonises disturbed areas where there is little competition.
Plant is extremely small and only grows up to 200 mm. Roots are arranged in bundles or clusters; they are swollen, brown and hairy. Stems are erect without creeping rhizomes, with a few reduced sheaths at the base. It has many overlapping leaves. Inflorescences are shaped like straight tubes, with many overlapping flowers; flower clusters are sharply pointed, overtopping the flowers. Flowers are 3 mm long, white with a yellow lip. Sepals are narrow ovate, apically hood-shaped. Gynostemium (column in the centre of flowers formed by the union of the stamen with part of the gynoecium) is 1 mm tall, stigma is broad, rostemium lobes are 0.5 mm long, spreading. It flowers from July to September.
Very little is known about Zeuxine africana. Its single known subpopulation in South Africa was established through immigration from another subpopulation beyond the borders of South Africa. Therefore, its conservation status was downgraded from Critically Rare to Endangered. Only nine collections are known from southern Africa.
Distribution and habitat
Zeuxine africana is not endemic to South Africa. The species has a narrow distribution along the Durban Bay shoreline, Nigeria and Angola. Plants were found growing in the dampish sandy, disturbed areas in Durban. Members of the KwaZulu-Natal node of the Custodians of Rare and Endangered Wildflowers (CREW) Programme have found approximately 80 plants within ±1 km distance this flowering season. The modified habitat in which this species grows suggests that it was accidentally introduced from its natural distribution. This species is not known to be in cultivation.
Derivation of name and historical aspects
The name of the family, Orchidaceae, is derived from the Greek word orchis that means ‘shaped like a testicle', in reference to the intricate flower. This genus name is from the Greek zuexis (united), for the partial union of the lip and column of the flower. Zeuxine is a genus with 76 species with one species known from southern Africa. For this reason, this species is named africana.
The story of Zeuxine africana in South Africa starts in 1895, when the German botanist Rudolf Schlechter described Zeuxine cochlearis from plants collected at the mouth of Umngeni River. The species name changed from Z. cochlearis to Z. africana. The rerouting of the Umngeni river mouth has resulted in the loss of the population at this site.
Zuexine africana is said to have a flower about three times the size of a match head and is self-pollinating. The presumed absence of the natural pollinating agents for Z. africana and 100% success of pollination among plants support this argument. On its tight head it carries between 4 and 40 flowers. Zeuxine africana has an interesting flowering pattern—when the lower seed capsules are ripe and split open, the top flowers are still open .
Uses and cultural aspects
There are no known uses and cultural aspects for this peculiar species.
Growing Zuexine africana
This plant is not know in cultivation and is not especially attractive. Anyone wishing to try it should note that it occurs on the coast and seems to prefer disturbed areas with little competition and is self pollinating.
References and further reading
- Victor, J.E. & Von Staden, L. 2006. Zeuxine africana Rchb.f. National Assessment: Red List of South African Plants version 2013.1 . Accessed on 2013/08/21
- Linder, H.P. & Kurzweil, H. 1999. Orchids of southern Africa . A.A. Balkema, Rotterdam.
- Dave's garden website: http://davesgarden.com/guides/botanary/
- Crouch, N., McDonald, G., Ngwenya, A., Nichols, G., Sikhakhane, B. & Singh, Y. 1994. Zeuxine africana : Durban's odd-ball orchid. South African Orchid Journal 25(4):127–129.
CREW Programme: KwaZulu-Natal node