Family Description
Plants perennial, terrestrial, epiphytic or lithophytic, sometimes mycotrophic; growth monopodial or sympodial; roots adventitious, often aerial, sometimes assimilatory. Stems usually leafy, often with one or more swollen internodes forming pseudobulbs. Leaves usually entire, alternate or opposite, often distichous, plicate or convolute; membranous to coriaceous, often terete or reduced to scale-like bracts, usually sheathed. Inflorescences erect or pendent; spicate, racemose or paniculate, 1- to many-flowered; basal, lateral or terminal. Flowers small to large; zygomorphic; sessile or variously pedicellate; resupinate or non-resupinate. Sepals three, free or connate; dorsal sepal often dissimilar to lateral sepals; lateral sepal sometimes adnate to the column to form a saccate, conical or spur-like mentum. Petals three (medial petal distinguished from the others as the lip), usually free. Lip entire or variously lobed, often with ornamented calluses, with or without a basal spur or nectary. Column short or long, with or without a basal foot, winged or lacking wings; fertile anther one (rarely two or three), terminal or incumbent, cap-like or dehiscing; pollen often agglutinated into discrete masses called pollinia; pollinia mealy, waxy or horny, soft or hard, sectile or not, 2,4,6 or 8, sessile or attached by caudicles or stipes to one or two viscidia forming a pollinarium; stigma 3-lobed, midlobe often modified to form a rostellum. Ovary inferior, unilocular with parietal placentation or rarely 3-locular with axile placentation. Fruit a capsule, usually opening laterally; seeds numerous, dust-like.
Genus Description
Plant terrestrial or occasionally epiphytic, small to medium; rhizome creeping, rooting at nodes. Stems erect, leafy. Leaves basal or clustered, fleshy, several, usually petiolate from inflated sheaths, sometimes reticulately patterned. Inflorescence terninal, erect, few-to many-flowered, racemose; peduncle and rachis to the floral axis or with lateral sepals spreading; dorsal; dorsal sepal forming a hood with petals. Lip unlobed, hollow or saccate at base, often setose within, narrowed to an acute apex which is often deeply cleft, granulose, pyriform or clavate; viscidium elongate.
Species Description
Plant up to 1m tall; rhizome stems-like, decumbent, rooting at the nodes. Stem erect, leafy in the basal third, bearing 3 or 4 sheaths above, 25-50cm tall. Leaves linear-lanceolate to ovate-lanceolate, petiolate, acuminate, 11-17 x 3-6cm; petiole sheathing at base, 5-8cm long. Inflorescence densely many-flowered; rachis 12-30cm long; floral bracts ovate-lanceolate, acuminate, margins ciliate, 0.5-1cm long. Flowers subglobose, 3-4mm across, uniformly white; pedicel and ovary twisted, 3-5mm long. Sepal similar, ovate to ovate-elliptic, acute or obtuse, glabrous, 2-3mm long. Petals spathulate, acute, forming a hood with the dorsal sepal, 2-3mm long. Lip subglobose-saccate, 1.5-2.5mm long; disc covered with pellucid glands; ape x recurved, with 2 white tubercles at the base. Column fleshy, 1-1.5mm long; rostellum divergent, finely streaked. Fruit ovoid, 4-5 x 2-3mm.
