Centrostigma Schltr. in Bot. Jahrb. Syst. 53: 522 (1915).
Description:
Plants terrestrial, perennating with tuberous roots; stems leafy; leaves linear-Ianceolate, imbricate, grading apically into the floral bracts. Inflorescences terminal, to 20-flowered; bracts leafy, green, about as long as the pedicels plus ovaries. Flowers resupinate, medium to large, white, cream-coloured or green. Sepals unequal; median galeate; lateral s obliquely spreading. Petals like the lateral sepals but smaller. Lip united with the gynostemium at the base, deeply 3-lobed; side lobes in our species fringed; spur cylindrical. Gynostemium erect, short; anther curved; pollini sectile, with the caudicles and viscidia separate; stigma developed into distinct processes, each one bilobed above the base, with the lower lobe receptive and the upper sterile; rostellum 3-1obed, central lobe small, lateral lobes upcurved.
Type species: Centrostigma occultans (Welw. ex Rchb.f.) Schltr.
Distribution:
Tanzania to S. Africa
Notes:
On account of a very similar structure also this genus was in the past included in Habenaria, but differs in the longitudinal division of the stigmatic processes. It may well be a specialized group within Habenaria which merits sectional rank rather than that of a separate genus (Kurzweil & ] Weber 1992). However, in the absence of a careful, comparative treatment of Habenaria, it is here retained as a separate genus.
Cultivation:
Not in cultivation
Species:

World Checklist of Selected Plant Families. The Board of Trustees of the Royal Botanic Gardens, Kew. Published on the Internet; http://www.kew.org/wcsp/ accessed 1/16/2010
Bibliography and References:

Kurzweil H, Weber A. 1992 Floral morphology of southern African Orchideae: II. Habenariinae. Nordic J. Bot. 12. 39-61. Bonatea, Cynorkis, Habenaria, Platycoryne, Stenoglottis, Centrostigma, Roeperocharis. Gynostemium development.