Disperis ciliata Bosser, 2002

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 : 64

6. Disperis ciliata Bosser , sp. nov.

Affinis Disperis latigaleatae H. Perrier sed petalis ad marginem ad apicemque longe ciliatis, et lobo mediale labelli triangulare satis differt.

TYPUS. — Humbert & Capuron 25002, Madagascar, mountains N of Mangindrano (High Maevarano, near the summits of Ambohimiravavy (Central–North), 1800-2000 m, 19 Jan.-12 Feb. 1951 (holo-, P!; iso-, K!, MO!, P!). Known only from the type collection.

A terrestrial herb, 15-20 cm tall. Stem slender glabrous. Leaves 2, opposite, inserted shortly above the middle of the stem, lanceolate, acute, rounded at the base and retracted into a short petiole, 2-4.5 × 0.8-2 cm. Inflorescence 2-5-flowered; bracts ovate, acute, those at the base largest, leafy, up to 8 × 5 mm. Flowers rose-coloured; pedicel and ovary 7-10 mm long. Dorsal sepal narrowly lanceolate to linear, acute, 7 × 1.5 mm, glabrous, with a median nerve and two fine lateral ones. Lateral sepals obliquely and broadly ovate, obtuse, connate at the base for about 2.5 mm, lacking a spur or gibbosity, 7.5 × 5.5 mm. Petals broadly and obliquely ovate, 6-6.5 × 4.5 mm, rounded at the tips, with the margins and apical part longly ciliate, adnate to the dorsal sepal to form a very concave hood of 6 × 6 mm. Lip 3-3.5 mm long; basal part linear, attached to the column for 1.7-1.9 mm; terminal part enlarged into a trilobed appendix, the lateral lobes linear, curved, involute on the margins, dilated-claviform at the apex, more or less 2 mm long; mid-lobe triangular, of the same length or a little longer than the side lobes, the upper face of the 3 lobes densely covered with a short papillose pubescence. Rostellar arms 1.7-1.8 mm long, slightly curved and spathulate at the apex. — Fig. 6D.

DISTRIBUTION. — Madagascar; endemic.

HABITAT. — Under trees in humid montane forest on laterite of gneiss, transition to lichenrich forest; 1700-1900 m.

Because of its habit and the general appearance of its flowers, this species recalls D. latigaleata . It can be readily distinguished, however, by its ciliate petals and by the terminal appendage of its lip in which the midlobe is relatively short and covered by a short papillate pubescence while in D. latigaleata that lobe is lengthened into a linear glabrous extention which is slightly dilated at the tip. The lip appendage also resembles that of some forms of D. oppositifolia , but the flower is glabrous, with the lateral sepals more extensively connate and contracted at the narrow base.

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).