大叶蛇根草 da ye she gen cao

Herbs, erect, to 100 cm tall; stems drying dark brown, rather stout, glabrous. Leaves in subequal pairs; petiole 0.8-1.5 cm, glabrous; blade drying papery, adaxially grayish green, abaxially pale green, broadly ovate, ovate, or elliptic, 15-22 × 6-10 cm, glabrous on both surfaces, base obtuse then abruptly narrowed, apex cuspidate; secondary veins 11-16 pairs; stipules caducous, not seen. Inflorescences congested-cymose to subcapitate, many flowered, ca. 3 cm in diam., mealy pubescent; peduncle ca. 1.5 cm; axes helicoid; bracts absent. Flowers reportedly distylous. Calyx mealy pubescent; hypanthium broadly turbinate, ca. 2.1 mm; limb tubular, ca. 1.5 mm, undulate to shallowly 5-lobed. Corolla green, rather stoutly tubular, mealy puberulent outside; tube ca. 5.5 mm, white villous above middle inside; lobes triangular-ovate, ca. 1.5 mm, dorsally broadly winged and with horn ca. 0.5 mm near apex. Capsules unknown. Fl. Nov.

● Forests in ravines; ca. 1100 m. Yunnan (Jinghong).

The original description (H. S. Lo, Bull. Bot. Res., Harbin 10(2): 79-80. 1990, not validly published) noted that the flowers are distylous but described only a presumed long-styled form, with the anthers positioned near the middle of the corolla tube and the stigmas positioned at or just above the corolla throat.