Flowering plant 4–18 cm tall. Leaf cordate, thin, 15–30 mm long, 12–25 mm wide, green above, reddish-purple (rarely greenish) beneath, entire or sometimes shallowly lobed. Flowers 1–18, translucent green or pinkish with reddish veins and spots, labellum green to reddish-purple; pedicel (including ovary) 4–6 mm long, subtended by small bract; dorsal sepal hooded, linear-obovate, 5–8 mm long, apical point c. 1–2 mm long; lateral sepals projected obliquely forwards, parallel, crossed or divergent, linear to linear-oblanceolate with fine point, similar in length to dorsal sepal; petals spreading or reflexed, linear-ovate to ovate, c. 3 mm long. Labellum on short claw, slightly decurved distally, oblong-ovate to ovate-lanceolate, 3–5 mm long, 2–3 mm wide; base of lamina broadly wedge-shaped or squarish with rounded corners, margins revolute, entire, apex with short point; callus thick, fleshy, smooth or slightly papillose towards the apex. Column incurved, almost terete, not winged. Flowers Apr.–Aug.