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
Petals epiphytic or lithophytic, small to large; rhizome short to long, creeping to pendent, covered by scarious sheaths. Pseudobulbs stout, sessile, often angled, distant or clustered on rhiozome. Leaves 1 or 2 from pseudobulb apex, thin textured to coriaceous, erect, suberect, spreading or pendent. Inflorescence lateral, arising from pseudobulb base, racemose to capitate, 1 to many flowered; rachis sometimes flattened. Flowers minute to large, occasionally showy. Dorsal sepal free; lateral sepals connate at base to column foot to form a saccate mentum(sometimes cannate above). Petals free. Lip simple to 3 lobed, sometimes fleshy, often ciliate or pubescent, ± recurved. Column short, erect with ± terminal, aristate teeth or wings; anther terminal; pollinia 4, waxy; naked, viscidium or hamular stipe sometimes present.
Species Description
Plant epiphytic or lithophytic; rhizome creeping, slender, woody, 1-2mm thick; root clustered at nodes, Pseudobulbs erect, cylindric, smooth to rigid, 2-3.5 x 0.3-0.6cm, inserted at intervals of 4.5-7.5cm along rhizome, leaf 1, oblong-elliptic to oblong-lanceolate, ape x emarginate, subsessile to shortly petiolate, 6-9 x 1.3-1.9cm; petiole 1-3mm long. Inflorescence 1 or 2, basal from pseudobulb, capitate, densely many flowered; peduncles sheathed, 3.5-8cm long; sheath imbricate, lanceolate, tubular, 0.5 (at base)-1.8cm long, mouth wide; floral bracts lanceolate, acute to acuminate, concave, 3-veined, 4-8 x 1-2mm. Flowers strongly fragrant, 5-7mm across; sepals and petals white tipped with yellow, lip white to pale orange; pedicels and ovary slender, 3-5mm long. Dorsal sepal lanceolate, acuminate to subcaudate, falcate, 0.4-1.1 x 0.1-0.15cm. Petals spreading, ovate, obtuse, 1-veined, 1-1.5 x 0.5-0.7mm. Lip simple, fleshy, oblong-lanceolate, centrally grooved, glandular pubescent, margins grandular-pubescent, 1.5-1.8 x 0.4-0.7 mm. Column stout, 0.4-0.6mm tall, stelidia short; foot short; anthers papillose.
