Plant at fl. to 70 cm. tall. Tuber to 5 × 1 cm. Stem stiffly erect, axis of raceme often flexuous. Lvs linear-lanceolate to linear, channelled, acute, shorter than stem. Raceme to c. 20 cm. long; fls 2–12, well separated. Per. green to dull reddish, often with varying amounts of the two colours. Dorsal sepal 1–1.5 cm. long and almost as wide, deeply concave, subacute; laterals to twice as long, c. 0.5 mm. diam., semi-terete, erect or diverging. Petals narrow-oblong, flat, us. notched at tip. Labellum spreading or deflexed, of firm texture with smooth margins; lateral lobes broad, oblique; mid-lobe larger, ovate; median callus near base, shortly conical with thick tip turned inwards, often yellow; 2 smaller lateral basal calli us. present. Processes of column-wings linear, ± papillose, almost as long as anther.