Epiphytic herbs with creeping rhizomes. Stems flattened, slender, of many internodes, surrounded by overlapping sheaths of leaves. Leaves distichous, narrow, articulated with rigid sheaths. Flowers inconspicuous, in crowded terminal head subtended by many long chaffy sterile bracts or scales; sepals and petals similar, petals often narrower; lip adnate to base of column, saccate at base, with a flat or concave limb at apex, often transversely ridged betweeen base and limb; column short and stout, foot hardly developed; anther terminal, incumbent, mainly 2-celled; pollinia 8, waxy, laterally flattened, connate by short caudicles; stigma entire.
About 100 species, from the Seychelles to the Pacific, most abundant in Indonesia, Philippine and New Guinea. One species in Taiwan.