A comparative study of the floral morphology in the genus Disperis (Orchidaceae)
Kurzweil, H.; Linder, H.P.
Beitrage zur Biologie der Pflanzen 66(3): 433-477
The floral morphology of selected species of the genus Disperis (Orchidaceae-Orchidoideae-Coryciinae) is surveyed. The study concentrates on the little known tropical species of the genus, supplementing previous studies on the South African species, which are structurally rather different from most tropical species. Minute teeth adpressed to the rostellum just above the lip insertion, interpreted as vestiges of the lateral carpels (lateral stigma lobes), were observed in many tropical and some South African species, and appear to be the basic condition in Disperis. The congenital fusion of the lip to the gynostemium, which is often quoted as being one of the main characters of the Coryciinae, is shown to be completely or almost completely absent in a few species. The lateral gynostemium appendages are distinctly bi-partite in many species, with a prominent, smooth, erect portion and a small, sculptured, horizontal portion. This is suggestive of their derivation from basal bulges (staminodes) and auricles (filament appendages), which appears to be the general situation in the subfamily Orchidoideae.