对生蛇根草 dui sheng she gen cao

Herbs, weak to ascending, to 70 cm tall; stems generally terete, hispidulous to glabrescent. Leaves in subequal pairs; petiole 1-2 cm, subglabrous or puberulent; blade drying papery, brown, narrowly elliptic, ovate, or lanceolate, [3-]8-15 × [1-]3.5-6 cm, subglabrous or sparsely strigillose adaxially, pilose along principal veins abaxially, base cuneate then narrowed and shortly decurrent, apex shortly acuminate; secondary veins 9-11(-15) pairs; stipules caducous or persistent on upper nodes, linear or bifid, 2-11 mm, puberulent. Inflorescence terminal and/or paired in upper stem nodes, cymose to paniculate, many flowered, ferruginous puberulent; peduncle 2-4 cm; axes helicoid; bracts minute, caducous. Flowers with biology unknown, subsessile. Calyx pubescent; hypanthium ellipsoid, ca. 1 mm; lobes triangular, ca. 0.3 mm. Corolla white, tubular-funnelform, outside glabrous; tube ca. 4[-8] mm, inside glabrous or densely barbate in throat; lobes oblong-triangular, ca. 2 mm, dorsally ridged, apex rostrate. Capsules drying yellow, mitriform-obcordate, ca. 2 × 6-7 mm, subglabrous. Fl. winter and spring.

Wet places in forests; [below 100-1500 m in Myanmar]. Hainan, Yunnan [NE India, Myanmar].

Deb and Mondal (Bull. Bot. Surv. India 39(1-4): 86-87. 1997) described this species as annual and the flowers as variously glabrous inside or densely barbate in the throat. Measurements in brackets above are taken from their description and may be expected in Chinese plants.