大齿蛇根草 da chi she gen cao

Large herbs or subshrubs, erect, to 2.5 m tall; stems drying black to brownish red, ferruginous pilosulous to glabrescent. Leaves in subequal pairs; petiole 1-2 cm or sometimes longer; blade drying papery, adaxially grayish brown, abaxially pale, oblong-elliptic, ovate-oblong, or ovate, 6.5-17 × 2.5-5.5 cm, glabrescent on both surfaces or sparsely pilosulous adaxially and pilosulous along principal veins abaxially, base cuneate then decurrent, margins entire, apex acuminate; secondary veins 14-16 pairs; stipules ovate to lanceolate-ovate, 5-16 mm, entire or occasionally dentate, parallel-nerved, subglabrous, acuminate. Inflorescence cymose to congested-cymose, many flowered, pendulous then becoming erect, densely ferruginous hirsute or -hirtellous; peduncle ca. 1 cm; bracts sublinear, 7-9 mm, ciliolate, glabrous or sparsely pilose, persistent. Flowers reportedly distylous, on pedicels 1-1.5 mm. Calyx hispidulous; hypanthium obrhombic, ca. 1 mm, weakly 5-ribbed; lobes narrowly lanceolate, ca. 2.5 mm. Corolla greenish yellow in bud, reddish at anthesis, tubular-funnelform, glabrous outside; tube 13-14 mm, villous inside; lobes subovate, ca. 2 mm, dorsally with wing to 0.6 mm wide, apex rostrate. Capsules obcordate, 2.5-3 × 7.5-9 mm, hispidulous. Fl. Sep.

● Wet places in forests; ca. 1500 m. Yunnan.

In the protologue and FRPS (71(1): 126-127. 1999), H. S. Lo described the flowers as distylous with the long-styled flowers unknown; the putative short-styled flowers were described as having the anthers partially exserted in the throat and the stigmas situated below the middle of the corolla tube.