厚柄茜草 hou bing qian cao

Vines, herbaceous, climbing, to 3 m; stems quadrangular becoming subterete, tuberculate-hispid, scabrous. Leaves in whorls of 4, often ± unequal; petiole 0.5-1.8 cm or smallest leaves sometimes subsessile; blade drying thickly leathery, ovate-oblong to elliptic, (0.7-)2-4.5 cm, tuberculate-hispid, base rounded to cordulate, margin slightly revolute, apex obtuse; principal veins 5, palmate. Inflorescences thyrsoid, paniculate, 3-7 cm, with axillary and terminal cymes; axes rather stout; bracteoles ovate or lanceolate, 2.5-3.5 mm. Flowers unknown. Immature mericarp berry black when dry, ca. 4 mm in diam. Fr. autumn.

Forest margins on mountain ridges; 1400-2400 m. Yunnan [Myanmar, Thailand].

We have seen no authentic material of Rubia crassipes. The above description corresponds to the protologue and to H. S. Lo (in FRPS 71(2): 313. 1999). The extended description and photo of plants from Thailand regarded as this species by Puff (Fl. Thailand: Rubiaceae; http://homepage.univie.ac.at/christian.puff/FTH-RUB/FTH-RUB_ HOME.htm; accessed on 5 Oct 2010) deviates by straight and soft hairs in addition to the scabrous indumentum and considerably larger leaves. Puff also added data on the shallowly campanulate, 5-lobed flowers 2.4-4 mm in diam., and considered the taxon as part of the R. cordifolia group. Only further extensive studies will clarify the doubtful delimitation and taxonomic placement of R. crassipes.