Description: Lianas, sparsely tomentellous to glabrous. Leaves alternate, board ovate or suborbicular, 7–19.5 x 4–18 cm; base emarginate to cordate; blade tomentellous below; petiole 1.5–7 cm long. Inflorescence paniculate; bracts ovate; bracteoles 3, sepal-like, unequal; pedicels 8–10 mm. Flowers fragrant; sepals free, quincuncial, unequal, outer 3 ovate-oblong, 3–4 mm long, longitudinally ridged, tomentose; inner 2 smaller. Corolla narrow funnelform, 2–3 cm long, white; tube widening gradually from base upward; limb 1.7–2.7 cm diam., obtusely 5-lobed; stamens 5, unequal, 0.8–1.2 cm; anthers sagittate, versatile, not spiny. Disk absent. Ovary unilocular glabrous; ovules 4; pistil 1–1.3 mm long; style basally pilose; stigma 2-lobed, wrinkled. Fruit an indehiscent utricle, obovoid, c. 6 mm long (immature), yellowish tomentose; outer 3 fruiting sepals spathulate, 5–5.5 cm long, with 7–11 longitudinal veins bases thickened, keeled, clasping fruit. Seed 1, ca 5 mm long, dark brown to blackish, glabrous. |
| Distribution: Distributed in Assam, Myanmar, Laos, N, NE & SW Thailand, recorded from Mae Hong Son, Chiang Mai, Nan, Lampang, Phrae, Phetchabun and Kanchanaburi, on limestone in mixed deciduous forest, 100–700 m. |
