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 epiphytic, lithophytic or terrestrial, usually autotrophic, rarely mycotrophic(when lacking leaves); roots caespitose. Pseudobulbs short to elongate, covered by bladeless sheaths. Leaves long, oblong or rarely lanceolate, coriaceous. Inflorescence erect or curved, suberect or pendent, racemose, 1 to many flowered; peduncle loosely sheathed. Flowers often large and showy. Sepals and petals free, spreading or erect. Lip 3 lobed, sessile, borne on a short column foot; lateral lobes erect around the column; mid lobe recurved; disc with 1-3, glabrous or pubescent, ridges. Column long; pollinia 2(with deep grooves) or 4, subglobose or pyramidal, attached by a short caudicle to a broad viscidum.
Species Description
Plant epiphytic or lithophytic, 25-40cm tall; roots cauline. Pseudobulbs stem like, surrounded by numerous, persistent leaf sheaths. Leaves 6-17, apical from pseudobulb, distichous, narrowly oblong, tapering, ape x acute, unequally 2 lobed, mucronate, 16-50 x 0.8-1.8cm; leaf bases sheathing, persistent, 6-10cm long, margins membranous. Inflorescence curved to pendent, densely 5 to 10 flowered; peduncle suberect, sheathed, c.16cm long; sheaths 6-8, boat shaped to cyclindric, e x panded, 10-14cm long; rachis 5-10cm long; floral bracts triangular, acute, 2-7mm long. Flowers fragrant, not opening fully, c.6mm across, white or pale pink, lip with a yellow patch at base, callus bright yellow, column white to pale green; pedicel and ovary 1.6-2.5cm long. Sepals similar, narrowly oblong to obovate, acute, concave, porrect, 4.3-5.2 x 0.8-1.1cm; lateral sepals weakly falcate. Petals narrowly oblong to oblong ovate, weakly falcate, porrect, 3.9-4.9 x 0.5-0.7cm. Lip 3 lobed, elongate, adnate to the column base for 3-5mm; lateral lobes broad, clasping the column, puberulent, broadly rounded to subacute, margins fringed, 1-1.2cm; midlobe small, ovate, rounded or mucronate, porrect, puberulent, margins undulate, 1-1.3 x 1-1.3cm; callus long, 2 ridged. Column slender, narrowly winged, 3.3-3.6cm long. Fruit broadly ellipsoid, c.3 x 2.5cm.
