Disperis Sw. subgen. Disperis, Sw. subgen. Disperis, 2005

Kurzweil, Hubert & Manning, John C., 2005, A synopsis of the genus Disperis Sw. (Orchidaceae), Adansonia (3) 27 (2), pp. 155-207 : 188-189

Disperis Sw. subgen. Disperis , subgen. nov.

Glabrous or hairy herbs. Leaves mostly alternate, very rarely basal, opposite or absent. Median sepal mostly ovate or lanceolate and galeate, lateral sepals almost always free; lip appendage entire but sometimes apically bifid, often hairy or papillate. Rostellum arms mostly twisted. Pollen rugulate.

DISTRIBUTION. — Thirty species, mainly in southern Africa but ranging into the tropics of Africa and Madagascar.

GROUP 5: “MICRANTHA GROUP” (SPECIES 45-52); FIGURE 8

Almost always glabrous herbs. Leaves two, mostly alternate, rarely opposite or absent. Hood deep or spurred, lateral sepals free or fused at very base; lip claw weakly or extensively fused with gynostemium, blade flexed forward, flap-shaped or triangular, flat or convex, small in relation to appendage. Rostellum arms short and twisted outwards.

DIAGNOSIS AND RELATIONSHIPS. — This group is characterised by a small, convex lip blade corresponding to the “ Cardiophora type ” of KURZWEIL F LINDER (1991), and by their short, twisted rostellum arms. The southern African species included here were retrieved as several clades in the cladistic study of MANNING F LINDER (1992). Within the group, Disperis micrantha and D. disaeformis were regarded as sister species, defined by the peculiar, reflexed and apically strongly papillate lip appendage.

Five tropical African species, Disperis breviloba , D. galerita , D. kilimanjarica , D. meirax and D. parvifolia have a remarkably similar lip structure and are probably closely related. A possible relationship between D. breviloba and D. par vifolia was suggested by VERDCOURT (1977) and the similarity of the lip of D. galerita with that of D. kilimanjarica was noted by CRIBB F THOMAS (1997). The poorly known D. meirax was also associated with D. galerita ( SCHLECHTER 1898) .

DISTRIBUTION. — Southern and tropical

Africa.

Figures

FIG. 8. — Flowers and floral details in the “Micrantha group”: A, B, Disperis woodii Bolus: A, flower; B, lip and gynostemium; C, D, D. disaeformis Schltr.: C, flower; D, lip and gynostemium; E-G, D. kilimanjarica Rendle: E, lip and gynostemium; F, lip; G, gynostemium. Drawn from alcohol material: A, B, Batten s.n.; C, D, source unknown; E, F, Mabberley & McCan 13; G, Dowsett- Lemaire 352.