Herbs, terrestrial or rarely epiphytic. Rhizome creeping. Stem erect, cylindric, reedlike, many noded, enclosed in tubular sheaths toward base, leafy above. Leaves many, plicate, base decurrent into an amplexicaul sheath, articulate. Inflorescences usually 1-3, arising laterally from nodes in lower half of stem, erect or ascending, racemose; peduncle with several amplexicaul sterile bracts at base; rachis many flowered; floral bracts caducous, lanceolate. Flowers spreading horizontally or nodding, small to medium-sized, opening widely or not. Sepals and petals similar, free, spreading to reflexed; petals sometimes broader than sepals; lip adnate to base of column, 3-lobed above middle, spurless but base shallowly saccate or concave; lateral lobes erect, loosely embracing column; mid-lobe expanding from a short claw, usually 2-lobulate, apical margin usually strongly crisped; disk sometimes with a callus composed of 2 ridges. Column stout, winged, slightly dilated at base but without a column foot; anther terminal, incumbent; rostellum ovate, small; stigma subterminal, suborbicular; pollinia 8, in 2 groups of 4, equal in size, narrowly obovoid, waxy, borne on a globose viscidium.