Fls solitary, occ. 2; floral bracts us. 2, one minute, the larger us. shorter than ovary. Per. often large for size of plant; dorsal sepal uppermost, curved forward, ± concave to galeate; lateral sepals and petals linear to filiform, greatly elongate to extremely small. Labellum relatively large, the basal edges overlapping behind the column to form a tube, the distal part ± cylindric or expanded into a broad, abruptly deflexed lamina; margin entire, denticulate or fimbriate; calli if present minute and papillose. Column short, ± curved, us. inclined backwards, wings occ. represented by small lobes near top; anther terminal, erect, pollinia 2 per cell, pollen finely granular; stigma discoid, surrounded below by a fleshy ridge; rostellum median. Plants terrestrial, glab.; tubers orbicular, us. terminal on long laterals arising in axils of scale lvs on buried part of stem. Fl.-stem short, elongating greatly as fr. matures. Green lf solitary, broad, lamina us. horizontal. About 50 spp. from south-east Asia to N.Z., the 8 N.Z. spp. including 2 known also from Australia.