Erect herb, 15–30 cm. Rhizome ca. 22 by 5 mm, cylindric, scales 5.5–8 by 1–2.3 mm, narrowly ovate to elliptic-ovate. Stems 2–6 cm long, to 1.3 mm in diam., terete with 5–7 shallow longitudinal ridges. Leaves, 1 per stem, 7.1–8.8 by 3–4 cm, ovate to ovate-sagittate or ovate-oblong, sometimes narrowly elliptic or linear-lanceolate (in Sri Lanka), chartaceous to subcoriaceous, base usually cordate to sagittate (in Thailand), sometimes cuneate to obtuse (in Sri Lanka), apex acuminate with a blunt tip; petioles overtopping the stem and pushing the fertile branch to one side, erect to ascending, 3.1–6.3 cm long, terete with ridges like stem. Flowers 5–15 mm in diam. when at anthesis, dark purple-brown, pedicels 10–32 mm long, terete; tepals free, chartaceous, with 5 longitudinal stripes (veins); outer tepals 5–7.6 by 2.2–2.5 mm, lanceolate-ovate, apices acuminate; inner tepals 4.3–5.2 by 2.3–2.6 mm, ovate to lanceolate-ovate, apices acute to acuminate; stamens inserted on torus, filaments, 2.2–2.6 mm long, anthers 0.6–0.75 by 0.25–0.45 mm, introse, connective ca. 8 mm long; ovary 1.6–2.4 by 1.9–2.2 mm, obovate in outline, with 3 shallow ridges; styles 3, 1.8–2.1 by 1.1–1.3 mm, erect, basal third fused, stigmas 0.3–0.5 mm long, recurved, bifid at the tip of each style. Fruits 10–16 by 9.5–11 mm, obovate, persistent tepals 1–4 mm long; fruiting pedicel 3.2–4.5 mm long. Seeds 2 per locule, 5.2–6.4 by 2.5–3.5 mm, ovoid to globose with irregular lobes.