Disperis leuconeura

Summerhayes, V. B., 1968, Orchidaceae (Part 1) part., Flora of Tropical East Africa 1 (1) : 222

5. D. leuconeura Schltr .

in E.J. 53: 549 (1915) & in E.R. Beih. 68, t. 44/173 (1932). Type: Tanganyika, Rungwe District, Kyimbila, R. Kibila, Stolz 1902 (B, holo. K, iso.!)

Glabrous herb, 4-5-15 cm. tall, arising from a globose hairy tuber ± 1 cm. in diameter. Leaves 2, opposite or subopposite, sheathing at the base, sessile, ovate or ovate-lanceolate, 0-6-2-5 cm. long, 0-3-1-2 cm. wide, acute at the apex, rounded or subtruncate at the base above the sheath, the main venation, particularly the midrib, white in both living and dry states. Racemes

1-2-flowered; flowers rose; bracts leaf-like, ± 7 mm. long, 3 mm. wide, acute. Intermediate sepal linear-lanceolate, 6 mm. long, joined to the petals to form an open boat-shaped hood; lateral sepals apparently not joined, obliquely falcate , ± 4 mm. long, 2 mm. wide, bearing sacs ± 1-1-5 mm. long. Petals elliptic, 5-5 mm. long, the free margin wavy. Lip 4 mm. long, with claw bent back over itself near base and bearing a papillate appendage with 2 curved lobes like the head of a buffalo (appearing rounded in immature flowers); claw terminating in a glabrous linear limb. Rostellum-arms very long, curved and thin, ± 2-5 mm. long. Fig. 39/5, p. 220.

Tanganyika. Rungwe District: Kyimbila area, R. Kibila, Feb. 1913, Stolz 1902!

Distr. T7; Malawi and Rhodesia

Hab. Leaf-mould in evergreen-forest; 900 m.

Note. The above description of the lip is taken from a Malawi specimen (McLoughlin 106). Schlechter describes a different structure, namely a claw which is widened at the apex into a papillate kidney-shaped dilation which bears just below the apex a papillate kidney-shaped appendage. The isotype is too poor to make out the flower structure but if the horns of the appendage were bent in then Schlechter’s description would fit better. If, as I assume, this appendage is homologous with the basal appendage in species 1-4 then the true appendage is obsolete in this species.