Herbs, terrestrial. Rhizome ascending, elongate, several noded, fleshy; roots arising from rhizome nodes, elongate, fleshy, pubescent. Stem glabrous, leafy. Leaves subrosulate or scattered along stem, narrowly ovate to elliptic, usually asymmetric, membranous to slightly fleshy, with a petiole-like base dilating into tubular amplexicaul sheath. Inflorescence pubescent, with a few scattered sheathing sterile bracts and several to many flowers in a terminal raceme. Flowers not resupinate; ovary not (or rarely slightly) twisted, glabrous or pubescent. Sepals free, similar, outer surface glabrous or pubescent; lateral sepals embracing base of lip. Petals connivent with dorsal sepal and forming inverted hood, usually narrower than sepals, membranous; lip adnate to margin of column, 2-partite or with a short mesochile and 3-partite; hypochile concave, saccate or cupular, containing 1 to several papillose, warty or lamellate calli on either side of midvein; mesochile (when present) with involute margin; epichile entire and tapering or 2-lobed. Column short, with thin to fleshy winglike appendages at apical margin; anther ovoid, 2-locular; pollinia 4, in 2 pairs, clavate, granular-farinaceous, basally attenuate into short caudicles, attached to solitary ovate viscidium; rostellum erect, relatively long, bifid; stigma lobes separate and placed at apical corners of column. Capsule erect, fusiform.
Column short, nearly as broad as long, with 2 parallel wing-like keels on the front; anther short; rostellum short and acute, or elongate, or linear-spathulate and obtuse; stigmas 2, convex, occasionally close together.
Lip concave, shallow, narrowed towards apex, basal part containing various glands and papillae
Flowers usually non-resupinate, less than 1 cm. long
Dorsal sepal and petals forming a hood; lateral sepals enclosing the saccate base of lip
Leaves variously arranged along stem, frequently with a long petiole arising from the persistent sheathing base, lanceolate, glabrous, soft, thin, varying shades of green
Terrestrial herbs up to 60 cm. high when flowering, not very rigid, with very slender creeping rhizomatous rootstock, often decumbent at base