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 rarely terrestrial. Stems either (a) rhizomatous, (b) erect and many-noded, (c) erect and 1-or several-noded from a many-noded rhizome, or (d) lacking a rhizome, the new stems many-noded, arising from base of the old ones; tough and fleshy, swollen at base or along whole length, often pseudobulbous and ± covered with sheathing leaf bases and bladeless sheaths. Leaves 1 to many, apical from psedobulb or arranged distichously along stem, linear-lanceolate, oblong or ovate, papery or coriaceous, apex usually 2-lobed or emarginate. Inflorescence racemose, 1-to many-flowered, erect, horizontal or pendent, lateral or terminal. Flowers often showy, resupinate or non-resupinate, ephemeral or long-lived. Sepals short to filiform; lateral sepals adnate to the elongate column foot to form a more or less prominent mentum; mentum often spur-like. Petals similar to sepals. Lip entire ro 3-lobed, base joined to the column foot, often forming a closed spur with the lateral sepals; disc 1- to 7-keeled, usually ecallose. Column short with apical stelidia; foot; polinna 4 in appressed pairs, naked.
Species Description
Plant epiphytic, pendent. Stem long, slender, branched, pendent, jointed, bearing few lwaves from the bead-like nodes; internodes ridged, 1-2.5mm thick, tubular-sheathed, 1-2cm long. Leaves few, linear-oblong, subacute, jointed with internode sheath, sessile, many-veined, 3-8 * 0.15-0.4cm. Infloroscence lateral, arising from nodes, 1 flower from each peduncle (occasionally a second peduncle arising with the pedicel creating a 2-flowered infloroscence); peduncle short, glabrous, sheathed at base, 1-2.8cm long; sheath 1, tubular, 4-6mm long; floral bracts ovate, obtuse, membranous, 5-6mm long. Flowers 3.4-5cm long; sepals and petals pale pink tipped with purple, lip white with a central dark purple spot surrounded by a yellow-orange ring, ape x purple; pedicel and ovary slender, glabrous, 1.5-1.8cm long. Sepals spreading, oblong-lanceolate, acuminate, sometimes twisted, 7-veined, 4-5 * 0.8-1.2cm; lateral sepals adnate at base to form a spur-like mentum; mentum 5-6mm long. Petals elliptic-ovate, acute to acuminate, 9-veined, 3.8-5 * 1.1-1.6cm. Lip obscurely 3-lobed, shortly clawed and hooded at base, broadly cordate-orbicular, ape x acute, softly ciliate, margins dentate-serrate to fimbriate, 3-4.9 * 1.8-3.5cm. Column 3-5mm long; stelidia 2, horn-like; anther cap hemispheric, dentate at ape x , glandular-pubescent.
