Description from Flora of China
Psychotria scandens Hooker & Arnott.
Climbing or creeping vines or lianas, to 6 m or more, rather fleshy, juvenile stems appressed to substrate with adventitious roots, reproductive stems spreading at apex; stems glabrous. Petiole 1-10 mm, glabrous; leaf blade drying papery to leathery, pale green, dark reddish green, reddish brown, or dark brown, often paler below, ovate or obovate on juvenile stems and elliptic, elliptic-oblong, lanceolate, oblanceolate, or obovate-oblong on reproductive stems, 0.7-9 × 0.5-3.8 cm, glabrous, base acute to obtuse, margins plane or sometimes thinly revolute, apex acute, obtuse, or sharply acuminate; secondary veins not visible or 3-10 pairs, not forming a submarginal vein, without domatia; stipules caducous, triangular to ovate, interpetiolar or shortly united around stem, 2-3 mm, glabrous, acute to rounded. Inflorescences terminal, cymose, glabrous to puberulent, few to many flowered, branched for 3-5 orders, pedunculate; peduncle 0.5-3 cm; branched portion corymbiform, 1-5 × 1-5.5(-10) cm; bracts subtending secondary axes 1-2 mm and triangular or often leaflike and 3-6 mm, those subtending pedicels triangular, 0.2-1.5 mm; pedicels 0.5-1.5 mm. Flowers pedicellate. Calyx glabrous to puberulent; hypanthium portion obconic, 0.8-1 mm; limb flared, 0.5-1 mm, partially lobed; lobes triangular, ca. 0.5 mm. Corolla white, funnelform, outside glabrous to usually puberulent; tube 1.5-3 mm, in throat densely villous; lobes ligulate-oblong, 1.5-2.5 mm. Drupes white, subglobose or ellipsoid, 4-7 × 2.5-6 mm, with pedicels to 5 mm; pyrenes shallowly 4- or 5-ribbed. Fl. Apr-Jun, fr. year-round.
This species is used medicinally.
W. C. Chen (in FRPS 71(2): 60. 1999) described the stems, petioles (but not the leaf blades), inflorescence axes, and calyces as spreading pubescent, but this has not been seen on any of the specimens studied nor reported by other authors.
This species is commonly collected and morphologically quite variable, including in drying color, leaf size and shape, inflorescence size, and fruit size. The climbing habit and white fruit of this species are unusual in the genus but similar to some other species of Asian Psychotria (Sohmer & Davis, Sida, Bot. Misc. 27: 1-247. 2007). The name P. ixoroides Bartling ex Candolle has been considered a synonym of P. serpens by some authors, notably Merrill, but Sohmer and Davis (loc. cit.: 41-45) considered P. ixoroides an accepted species in the Philippines. However, they did not make any comparison there with P. serpens. Psychotria serpens is also similar to P. sarmentosa Blume, which was considered a distinct species by Sohmer (in Dassanayake, Revis. Handb. Fl. Ceylon 6: 349-352. 1987) again without any comparison to P. serpens.
Thickets or forests in ravines, mountains, hills, flat lands; below 100-1400 m. Fujian, Guangdong, Guangxi, Hainan, Taiwan, Zhejiang [Cambodia, Japan, N Korea, Laos, Thailand, Vietnam].