Herbs, epiphytic, monopodial, small to moderate-sized. Stems enclosed by persistent leaf sheaths, rooting mostly from base or lower part. Leaves many, distichous, terete, subterete, or broadly subterete, fleshy, adaxially channeled, jointed and dilated into sheathing base. Inflorescences axillary, racemose, few to many flowered; rachis usually purple; floral bracts much shorter than pedicel and ovary. Flowers usually opening widely. Sepals subsimilar, dorsally usually ± carinate; lateral sepals often slightly larger, oblique. Petals similar to dorsal sepal; lip saccate or spurred, 3-lobed; lateral lobes erect beside entrance of spur, spotted; mid-lobe rather larger, often narrowed and with appendages at base; spur often cylindric and curved, attenuate toward tip, interior usually hispid papillose. Column short, thick, winged, with a very short but distinct foot; rostellum distinct, sometimes reduced, bilobed; pollinia 2, waxy, globose, porate, attached by a common, short, linear stipe to a broad viscidium.
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