Aopla Lindley; Monorchis Séguier.

Herbs, terrestrial, slender. Tubers globose to oblong-ellipsoid, undivided, fleshy, neck with several slender roots. Stem erect, with tubular sheaths at base, 1- to several leaved, glabrous. Leaves basal, green, elliptic to lanceolate, base contracted into amplexicaul sheath. Inflorescence erect, terminal, racemose, glabrous; peduncle often with 1 or more foliaceous sterile bracts; rachis laxly to densely many flowered; floral bracts lanceolate. Flowers erect, horizontal, or nodding, small, often spidery, resupinate or rarely not, usually yellowish green; ovary and pedicel straight, arcuate or sometimes distinctly hooked toward apex, twisted or rarely not, cylindric-fusiform, glabrous. Sepals subequal; dorsal sepal free or loosely connivent with petals and forming a hood; lateral sepals spreading. Petals smaller and narrower than sepals, usually thickened and fleshy; lip adnate to base of column, base shallowly concave or shortly spurred, margin entire, 3- or rarely 5-lobed. Column very short; anther adnate to apex of column, 2-locular, locules parallel; pollinia 2, oblong to ellipsoid, granular-farinaceous, sectile, each attached to a viscidium via a short caudicle; viscidia often involute and hornlike, naked; rostellum small, 3-lobed; stigma lobes 2, raised, clavate; auricles 2, usually prominent, placed laterally at base of anther. Capsule usually erect, oblong.

Herminium kamengense A. N. Rao (J. Econ. Taxon. Bot. 25: 287. 2001) was described from the region of the border of NE India and SE Xizang.

About 25 species: Europe, parts of SW and C Asia, extending to E and SE Asia and the Himalayas; 18 species (ten endemic) in China.

(Authors: Chen Xinqi (陈心启 Chen Sing-chi); Stephan W. Gale, Phillip J. Cribb)