Huang Teng Gen

Huang Teng Gen is the root (and woody stem) of Fibraurea recisa Pierre (Menispermaceae), a large woody dioecious vine of evergreen broadleaved forests in southern Yunnan, Guangxi, and Vietnam. The woody stem may reach 10 cm diameter and many meters in length, with a deeply furrowed grayish-brown bark; the wood and bitter yellow inner bark are intensely yellow due to high content of protoberberine alkaloids (palmatine, jatrorrhizine, berberine). Alternate, leathery, broadly ovate to elliptic leaves are 10-25 cm long, with three to five prominent palmate veins and long petioles. Small yellowish-green flowers in axillary panicles produce ellipsoid yellow drupes 2-3 cm long. Used in southern Chinese and Dai ethnomedicine to clear heat-toxin, treat dysentery, conjunctivitis, sore throat, and abscesses, the plant's alkaloid profile underlies its activity against enteric pathogens. Sustainability concerns have arisen due to wild harvesting.