蛇根草 she gen cao

Herbs or subshrubs, ascending, to 100 cm tall; stems glabrescent to puberulent. Leaves in subequal pairs; petiole 1.5-5 cm, glabrous to puberulent; blade drying thinly papery, elliptic or lanceolate-elliptic, 2.5-22 × 1-9 cm, glabrous adaxially, glabrous or puberulent on principal veins abaxially, base cuneate to obtuse, apex acute to acuminate; secondary veins 10-19 pairs; stipules deciduous, narrowly triangular, 4-8 mm, sometimes 2-lobed, glabrescent. Inflorescence cymose to paniculate, several to many flowered, puberulent; peduncle 0.5-6 cm; axes helicoid; bracts reduced and caducous or none. Flowers apparently distylous, subsessile. Calyx densely puberulent; hypanthium compressed turbinate, ca. 1 mm; lobes triangular, 0.5-1 mm. Corolla white, tubular or sometimes constricted near middle, outside puberulent to glabrous; tube 2.5-4 mm, inside villosulous near middle; lobes triangular, ca. 1 mm, dorsally smooth to costate. Capsules broadly mitriform, 1.5-3 × 3-9 mm, glabrous to densely puberulent.

Expected in Yunnan [India, Myanmar, ?Philippines, Thailand to Malaysia, ?Vietnam].

This species was not included for China by H. S. Lo (Bull. Bot. Res., Harbin 10(2): 1-82. 1990; FRPS 71(1): 110-174. 1999) but has been reported from the surrounding regions (Deb & Mondal, Bull. Bot. Surv. India 39(1-4): 67-73. 1997), and some specimens from China have been identified with this name by Chinese botanists (in herb.). The description here is presented at least for reference and is based on that of Deb and Mondal (excluding Ophiorrhiza mungos var. nemorosa (Thwaites) J. D. Hooker). Deb and Mondal (loc. cit.) reported O. mungos to flower and fruit throughout the year and did not describe its floral biology or individual floral forms but illustrated both short-styled and long-styled flowers.