40. Pecteilis Rafinesque, Fl. Tellur. 2: 37. 1837.
白蝶兰属 bai die lan shu
Authors: Xinqi Chen, Stephan W. Gale & Phillip J. Cribb
Herbs, terrestrial, medium-sized to large. Tubers solitary or paired, oblong, ellipsoid, or subglobose, undivided, fleshy, neck with several slender roots. Stem erect, often stout, leafy. Leaves cauline and alternate or in a basal rosette, ovate-elliptic or ovate, slightly fleshy, amplexicaul at base. Inflorescence terminal, with 1 to several flowers; floral bracts large, foliaceous. Flowers resupinate, often large, showy, usually white; pedicel and ovary twisted, usually slightly arcuate, narrowly fusiform. Sepals free, similar, broad; dorsal sepal erect; lateral sepals oblique. Petals linear-lanceolate, oblanceolate, or oblong, often narrower and smaller than sepals; lip decurved, irregularly ovate to flabellate, spurred, deeply 3-lobed; lateral lobes spreading, margin fimbriate-lacerate, denticulate, or rarely entire; mid-lobe straight, linear or broadly triangular; spur pendulous, straight to strongly curved, cylindric, often very long, much longer than ovary. Column erect, short; anther erect, 2-locular; locules widely spaced in a very broad connective; pollinia 2, granular-farinaceous, sectile; caudicles slender; viscidia small, each hidden in a tubular fold at end of rostellum arms; lateral appendages 2, elliptic, small, at base of anther; rostellum 3-lobed, lateral arms long, tapering, mid-lobe blunt; stigma lobes adnate to base of lip, connate, convex, sessile.
About five species: E and SE Asia, Himalayas; three species in China.