Family Orchidaceae Subfamily Epidendroideae Tribe Arethuseae Subtribe Arethusinae
Arethusinae Benth., J. Linn. Soc., Bot., 18 (1881.) 288, 347. Type genus: Arethusa L.
Terrestrial herbs. Roots with velamen. Stems reed-like or a corm, subterranean to areal exposed. Leaves 1 to numerous, conduplicate, distichous, often plicate, linear to lanceolate; leaf sheath present. lnflorescence terminal or lateral, branched or not, 1- to many-flowers; floral bracts often deciduous, ovate to linear, with acute to acuminate apex. Flowers resupinate or not. Sepals free to connate at the base, hardly spreading to strongly reflexed, elliptic, lanceolate to obovate. Petals free or not, hardly spreading to strongly reflexed, lanceolate, ovate, obovate to oblanceolate. Lip free or adnate to the column, 3-lobed with the lobes entire to crenate, obovate, obdeltoid to oblanceolate; lateral lobes usually basal, sometimes apical; midlobe entire to cleft; longitudinal keels present or not, often with coloured trichomes and papillae. Column straight to incurved, winged especially at the top; pollinia 4 or 8, more or less soft. Fruit a capsule, erect to pendent, fusiform, oblong, ovoid to obconical.
(after Goldman 2005)