Description from Flora of China
Involucraria lepiniana Naudin in Huber, Cat. 11. 1868.
Stem robust, branched, glabrous. Petiole 4-7 cm, striate, glabrous or glandular-punctate; leaf blade adaxially deep green, suborbicular, 9-17(-20) cm, shortly 3-5-lobed up to middle, adaxially rough; lobe margin denticulate, apex acute or shortly acuminate. Male raceme 13-17 cm; peduncle robust, striate, glabrous; pedicels ca. 5 mm; bracts suborbicular, ca. 4 cm, cucullate, margin lacerate; calyx tube attenuate from apex toward base, ca. 7 cm, puberulent; segments narrowly ovate, ca. 1.5 × 0.4 cm, margin laciniate. Female flowers solitary; pedicel 2.5-3 cm, glabrous, striate; bracts ovate, ca. 1.5 × 1 cm, entire; calyx tube ca. 4 cm; ovary ovoid, ca. 1.5 × 1 cm, glabrous. Fruit red, ovoid, ca. 9 cm in diam., smooth. Seeds brown, broadly ovate, ca. 1.5 × 0.8-1 cm, base obtuse or attenuate, apex truncate. Fl. May-Jul, fr. Aug-Nov.
De Wilde and Duyfjes (in Santisuk & Larsen, Fl. Thailand 9(4): 520. 2008) considered the Chinese material here treated as Trichosanthes lepiniana to represent a distinct species, T. inthanonensis Duyfjes & Pruesapan (Thai Forest Bull., Bot. 32: 86. 2004, type from N Thailand; the type of T. lepiniana is from peninsular India).
Evergreen broad-leaved forests along valleys, open forests and thickets on mountain slopes; 700-1200 m. SE Xizang, S and SE Yunnan [Bhutan, India].