Small to large, epiphytic or semi-epiphytic herbs or subshrubs with or without the stems swollen into pseudobulbs. Stems (secondary) swollen into pseudobulbs and the leaves borne at or near the apex of the pseudobulbs (? ENCYCLIUM); or the stems slender and not swollen and with the leaves scattered along the stem (? EUEPIDENDRUM); or slender or fusiform stems with the leaves scattered along them but with the base of the stems swollen (? BARKERIA). Leaves variable in shape and size, usually coriaceous but occasionally fleshy. Inflorescence commonly terminal but occasionally lateral or both terminal and lateral, rarely borne from lateral, leafless shoots which later develop into pseudobulbs or stems; from simple and often 1-flowered to compound and many-flowered. Flowers from small to relatively large. Sepals equal or subequal, spreading, reflexed or subconnivent. Petals similar to the sepals but usually smaller and narrower or even filiform, occasionally broader. Lip unguiculate; the claw free, partially free, or adnate to the column; lamina simple or 3-lobed, the lobes often lobulate; the disc ecallous or usually bicallous and with or without lamellae or additional calluses. Column stout or slender, alate or exalate, clinandrium variously developed. Anther terminal, operculate, incumbent, 2-celled and with each cell more or less divided by a septum; pollinia 4, uniseriate, laterally compressed, with appendages, rarely without, waxy. Capsule various, winged or wingless.