无柱兰属 wu zhu lan shu

Authors:Authors: Xinqi Chen, Stephan W. Gale & Phillip J. Cribb

Mitostigma Blume, Mus. Bot. 2: 189. 1856, not Decaisne (1844).

Herbs, terrestrial, slender. Tubers subglobose to ovoid, undivided, fleshy, neck with several slender roots. Stem erect, 1- or occasionally 2-leaved, glabrous or occasionally pubescent. Leaves basal or cauline, usually green and unspotted, rarely with purple-brown blotches, oblong, lanceolate, elliptic, or ovate, base contracted into amplexicaul sheath. Inflorescence a terminal raceme, glabrous; peduncle elongate, with 1 or more sterile bracts; rachis 1- to several flowered. Flowers often secund, resupinate, white, pink, mauve, or purple, rarely yellow; ovary usually straight, twisted, shortly pedicellate, cylindric-fusiform, glabrous. Sepals free, oblong to ovate, 1-veined. Petals free, often connivent with dorsal sepal and forming a hood, usually wider than sepals; lip spreading, spurred at base, 3-lobed; disk often papillose; mid-lobe often divided, forming 2 lobules; spur cylindric to narrowly conic, short to elongate. Column very short; anther usually erect, oblong-ellipsoid to obovoid, 2-locular, locules parallel or slightly divergent; pollinia 2, oblong, sectile, granular-farinaceous; caudicles straplike; viscidia naked, oblong-ovate; rostellum rather small, 3-lobed, base with ± ascending arms on both sides, margin adnate to column; stigma ventral, 3-lobed, lobes confluent, relatively large, flat to somewhat raised; auricles 2, large, stout, placed laterally at base of anther. Capsule suberect.

About 30 species: E Asia and adjacent areas; 22 species (21 endemic) in China.