Acanthephippium Blume, Bijdr. (1825) 353 ['Acanthophippium']
Sympodial terrestrial herbs. Roots few, short, unbranched. Rhizome short. Pseudobulbs closely approximate, conical to cylindrical with few internodes and 2-4 leaves, more or less covered by persistent sheath fibres, upper half covered by leaf-sheaths. Leaf articulate, glabrous, plicate, convolute, thin-textured, ovate to lanceolate-ovate to obovate; petioles sheathing, long or short. New shoot sprouting from the base of the mature pseudobulb, entirely covered by sheaths which become progressively larger towards the apex of the shoot. Inflorescence lateral from a lower node on the new shoot or from a lower node on the old pseudobulb, erect, short, peduncle more or less hidden by sheaths, a few-flowered raceme. Floral bracts foliaceous, cymbiform, often pale purple. Flower medium-sized to rather large, resupinate, fleshy, the sepals connate at the base forming an obliquely urceolate body, free at the top, the lateral sepals forming a mentum with the column-foot. Dorsal sepal oblong to obovate, concave; apex rounded to obtuse. Lateral sepals obliquely oblong; apex recurved and obtuse. Petals elliptic to spathulate, free, appressed to the sepaline tube. Lip more or less mobile, without spur, articulate on the apex of the long column-foot, 3-lobed or sometimes indistinctly 3-lobed; lateral lobes usually hatchet-shaped, erect; midlobe triangular to oblong, usually reflexed from the middle; disc with a varying number of longitudinal keels or thickening of the veins. Mentum formed by the lateral sepals and the column-foot, globose or spur-like. Column straight, broad, sometimes narrowly winged at the margin towards the apex; column-foot long, inflexed in the middle and slightly recurved towards the apex. Stigma broadly obovate to obovate; anther 2-celled, often with a rounded elevation, front margin drawn out in a flap, margin often erose, truncate or apiculate. Pollinia 8, ellipsoid, in two groups of 4, two of these larger, and two smaller, attached to caudicles, with a vsicidium, without a stipe. Ovary grooved, often sparsely and finely pubescent. Fruit held on long, erect stalks, ellipsoid, ridged.
(after Thomas, 1997, modified)