Description from Flora of China
Luffa cordifolia Blume, Bijdr. 929. 1826; Gymnopetalum piperifolium Miquel; Thladiantha calcarata C. B. Clarke; T. calcarata var. subglabra Cogniaux; T. calcarata var. tonkinensis Cogniaux; T. cordifolia var. tomentosa A. M. Lu & Zhi Y. Zhang; T. cordifolia var. tonkinensis (Cogniaux) A. M. Lu & Zhi Y. Zhang; T. globicarpa A. M. Lu & Zhi Y. Zhang; T. omeiensis T. Y. Zhu; T. tonkinensis Gagnepain; Trichosanthes javanica Miquel.
Vines, climbing, herbaceous, pubescent. Stems much branched, robust, angular-sulcate. Petiole slender, 4-10(-12) cm; leaf blade ovate-cordate, 8-15 × 6-11 cm, membranous or papery, adaxially scabrous, pubescent, or with setae on an enlarged base, veins densely pubescent, both surfaces densely pale yellow pubescent, basal vein along margin of base of blade, base cordate, margin irregularly dentate, apex acuminate or shortly so; sinus at base often open, sometimes closed, 1-3 cm deep, 0.5-2 cm wide. Tendrils simple, pubescent at first, glabrescent. Male flowers: 3 to several in dense short raceme; peduncle robust, 4-15 cm, pubescent; bracts imbricate, flabelliform, 1.5-2 cm, both surfaces pubescent; pedicels slender, ca. 5 mm; calyx tube campanulate, 5-6 mm, 5-partite; segments linear, ca. 10 × 1 mm, 1-veined, apex caudate-acuminate; corolla segments ovate or elliptic, ca. 17 × 7 mm, apex shortly acuminate or acute; filaments ca. 4 mm; rudimentary ovary semiglobose. Female flowers solitary; calyx and corolla as in male flowers; ovary oblong, base obtuse, pubescent; styles 3-fid; stigmas enlarged, reniform, 2-lobed. Fruit oblong, 3-5 × 2-3 cm, with scabrous rind, slightly pubescent, with 10 longitudinal striae, obtuse at both ends. Seeds broadly ovate, 4-5 × 3-3.5 mm, ca. 2 mm thick, reticulate. Fl. and fr. May-Nov.
De Wilde and Duyfjes (Blumea 51: 513-514. 2006) considered Thladiantha calcarata var. tonkinensis (as T. tonkinensis Gagnepain) and T. globicarpa to be species distinct from T. cordifolia, differing in their smaller, non-fenestrate fruit and the latter from the former by its narrower calyx segments.
After publication of the corresponding Flora of China volume, the following new combination was published: Thladiantha tomentosa (A. M. Lu & Z. Y. Zhang) W. Jiang & H. Wang (Nordic J. Bot. 28: 699. 2010), based on Thladiantha cordifolia var. tomentosa A. M. Lu & Z. Y. Zhang.
Streamsides, forests; 800-2600 m. Guangdong, Guangxi, Sichuan, Yunnan [India, Indonesia, Laos, Myanmar, Nepal, Thailand, Vietnam].