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
Plants terrestrial. Stems leafy, ascending to erect, rhizome decumbent, rooting at nodes. Leaves cauline, distant, few, petiolate, usually green on both surfaces. Inflorescence a laxly flowered spike or raceme. Flowers often showy. Sepals and petals free; lateral sepals spreading, oblique; petals connivent with dorsal sepal to form a hood. Lip 3-lobed, adnate to the column base, spreading; hypochile saccate, rounded to globose, enclosed by, or shorter than, the lateral sepals; mesochile channeled, long to shortly fimbriate-toothed; epichile unlobed or with a divergent 2-lobed blade; glands in spur not peltate, fleshy-linear. Column short, fleshy in front, winged or keeled. elongate; rostellum elongate, twisted; anther versatile; stigmas 1 or 2, ventral, under the rostellum; pollinia 2, granular.
Species Description
Plant 13-40cm tall. Stem glabrous, decumbent at base, 12-22cm long. Leaves ovate-lanceolate, acute, petiolate, distant along stem, green with white veins, 2-6 x 1-1.5cm; petiole 2-2.5cm long, base e x panded, tubular. Inflorescence la x y many-flowered; peduncle short, pubescent; peduncle sheaths 1 or 2, ovate-lanceoalte, acuminate, 0.6-1.2cm long; rachis pubescent, 4-12cm long; floral bracts ovate lanceolare, acuminate, 0.5-1.5 x 0.2-0.3cm. Flowers up to 2cm long; sepals and petals pale green, dorsal sepal tinged with brown, lip yellow, anther pink; pedicel and ovary 0.5-1cm long. Dorsal sepal ovate, acute, 5-7 x c.2mm; lateral sepals ovate-oblong, obtuse, spreading, 1-veined, 5-7 x 2-3mm. Petals reniform, acuminate, connivent with dorsal sepal to form a hood, 3-5 x 1-2mm. Lip 3-lobed, 0.7-1cm long; hypochile saccate with 2 spur-like processes; mesochile pectinate; epichile 2-lobed, lobes lateral. Fruit fusiform, sessile, erect, 1-1.2 x 0.3-0.5cm.
