Phaius Lour.

Herbs, terrestrial, with pseudobulbs, sometimes stemlike. Roots densely hairy. Pseudobulb sometimes stemlike, tufted, with few to many nodes, often sheathing, with several leaves on upper part. Leaves large, plicate, petiolate, apex acuminate to acute, with long, tubular sheath tightly embracing stem or sometimes equitant forming a pseudostem. Inflorescences 1 or 2, lateral on nodes of pseudobulb, higher or lower than leaves; peduncle with a few sparse sheaths; raceme with a few sparse or with many dense flowers, unbranched or rarely with a few branches at base; floral bracts large, apex acute; flowers ascending on raceme, often large. Sepals and petals subsimilar; lip adnate to column at base, separated from column or ± adnate to basal wings of column, base with short spur or spurless, nearly 3-lobed or unlobed, ± embracing column. Column long and stout, upper part enlarged, usually winged; rostellum large or inconspicuous, unlobed; stigma lateral; anther terminal, 2-locular; pollinia 8, waxy, in 2 groups, attached by caudicles to a sticky substance.

Some species grow in moist to wet soils in swamps and depressions, whereas others occur in forests growing on freely draining slopes or in accumulations of litter.