Description from Flora of China
Chavica mullesua (Buchanan-Hamilton ex D. Don) Miquel; C. sphaerostachya Wallich ex Miquel; Piper brachystachyum Wallich ex J. D. Hooker, nom. illeg. (included P. mullesua); P. guigual Buchanan-Hamilton ex D. Don.
Climbers woody, glabrous except for rachis and bases of bracts. Stems slender, hard, basal part tuberculate. Prophylls very short; petiole 0.7-2 cm, slender; leaf blade elliptic or narrowly elliptic or ovate-lanceolate, 7.5-9 × 3-4 cm, papery to thinly leathery, without glands, base cuneate, symmetric or slightly oblique, apex caudate-acuminate; veins 5(-7), abaxially very prominent, apical pair arising 1-2.5 cm above base, usually alternate; reticulate veins conspicuous. Flowers bisexual. Spikes leaf-opposed, at apices of branchlets, subglobose, ca. 3 × 2.5-3 mm; peduncle 2-3 mm; rachis pubescent; bracts orbicular, ca. 1 mm wide, peltate, abaxially glabrous; stalk short. Stamens 2; anthers reniform. Ovary obovoid; stigmas 3 or 4, very small. Drupe obovoid, ca. 2.5 mm in diam., partly immersed in rachis. Fl. May-Jul.
The very small bisexual inflorescences are easily overlooked at anthesis. Early botanists confused male plants of other species with Piper mullesua and wrongly described it as having slender, filiform male inflorescences (R. Wight, Icon. Pl. Ind. Orient. t. 1931. 1853; F. A. W. Miquel, Fl. Ind. Bat. 1(2): 446. t. 27 B. 1859; C. de Candolle in A. de Candolle, Prodr. 16(1): 388. 1868; J. D. Hooker, Fl. Brit. India 5: 87. 1886). Male plants of Piper thomsonii are similar to P. mullesua, but differ as follows: vines herbaceous; petiole longer; leaf blade usually oblique, obtuse or cordate at base, very minutely hairy along veins abaxially.
Forested slopes, valleys, ravines; 800-2100 m. Hainan, S Sichuan, S Xizang, Yunnan [Bhutan, India, Nepal]