Disperis perrieri Schltr.

Croix, Isobyl la, Bosser, Jean & Cribb, Phillip J., 2002, The genus Disperis (Orchidaceae) in Madagascar, the Comores, the Mascarenes and the Seychelles, Adansonia (3) 24 (1), pp. 55-87 : 71-72

10. Disperis perrieri Schltr.

Ann. Inst. Bot.- Géol. Colon. Marseille ser. 3, 1: 160 (1913); Feddes Repert. Spec. Nov. Regni Veg. Beih. 33: 109 (1925); H. Perrier in Humbert H. (ed.) , Fl. Madag., 49 e fam., Orchidées 1: 187 (1939); Du Puy et al., Orch. Madag.: 136 (1999). — Type: Perrier de la Bâthie 1924 (no. 39 of Schlechter), Madagascar, Manongarivo Massif, 1000-2000 m (holo-, P!, photo K!) .

Slender terrestrial herb 12-30 cm tall. Tubers 3-4, small, ovoid, oblong or linear. Leaves 2-4, alternate, rather irregularly spaced, 2.8-5 × 0.9- 1.2 cm, lanceolate, acute, clasping the stem at base, decreasing in size towards top of stem. Inflorescence 1-2-flowered; bracts lanceolate, acute, up to 8 mm long. Ovary and pedicel up to 10 mm long. Dorsal sepal 10 × 1 mm, linear; lateral sepals 8.5-10 × 3.5-4 mm, semi-ovate, free almost to base, each with a small, sac-like spur around the middle. Petals 12 × 6 mm, narrowing abruptly at base, longer than the dorsal sepal with which they form an open, obcordate hood 12- 15 mm tall, 16-20 mm wide above the middle but only about 2 mm wide at the base. Lip glabrous, 4.5 mm long, adnate to the column for 2 mm at the base and edged there with a crenate membrane; free part narrow at first then gradually enlarging to form a wide V, branches of the V elongate, c. 2 mm long, rounded at the tips, a little hooked, this V prolonged by a linear onenerved stipe, 3 mm long, 0.2-0.3 mm wide, bearing a terminal fleshy reniform appendage, 2- 3 mm long, concave obove and bearing a small papillose lobe in the middle. Rostellum arms short, c. 1 mm long. — Fig. 6H.

DISTRIBUTION. — Madagascar; endemic. HABITAT. — In humus and amongst lichens in damp woodland on gneiss; 1000-2250 m.

MATERIAL STUDIED. — MADAGASCAR: Humbert & Capuron 25758, Ambilobé Distr. , Marivorahona Massif, SW of Manambato, 2000-2244 m, 18- 26 Mar. 1951 ( K!, P!) ; Perrier de la Bâthie 1924 (no. 39 of Schlechter), Manongarivo Massif, in damp woodland, 1000-2000 m, May 1909 ( P!) .

This is a rare species that has only been collected twice in the NW of the island. Following the notes of PERRIER DE LA B ÂTHIE and HUMBERT, the stems are reddish, the leaves are dull green above with a paler median nerve and the under side is red. The lateral sepals are mauve or rose-coloured and the petals are rose-flushed or mauve on the back, paler on the inner surface. The hood is green on the back with three keels in relief, within on the inner face are a series of olive or brownish radiating lines.

Figures

Fig. 6. — Appendage of lip: A, Disperis majungensis (Perrier de la Bâthie 13038); B, Disperis cordata (Cadet C11, in alcohol); C, Disperis hildebrandtii (Hildebrandt 3158); D, Disperis ciliata (Humbert & Capuron 25002); E, Disperis lanceana (Lance s.n.); F, Disperis saxicola (Bosser 17168); G, Disperis humblotii (Humblot 1592); H; Disperis perrieri (Humbert & Capuron 25758); I, Disperis oppositifolia var. mascarenensis (Bosser 21622).