南丹蛇根草 nan dan she gen cao

Herbs, suberect, to 40 cm tall; stems drying black to brownish yellow, terete, glabrous. Petiole 1-2.5 cm, glabrous; leaf blade drying papery, dark gray or blackish gray adaxially, pale yellow or greenish yellow with veins brown abaxially, ovate to lanceolate, 4-11 × 1.5-4.5 cm, glabrous, base obtuse, apex acuminate; secondary veins 5-9 pairs; stipules caducous, not seen. Inflorescences congested, several flowered, pubescence in 2 pilose longitudinal lines; peduncle 1-2 cm; axes helicoid; bracts linear-lanceolate, 3-5 mm, weakly pinnately veined. Flowers distylous, sessile or subsessile. Calyx with hypanthium submitriform, ca. 1.5 mm, 5-ribbed; lobes triangular or narrowly triangular, markedly unequal, 1 or 2 larger ones 1-2 mm, 3 or 4 smaller ones ca. 0.7 mm, both lobes and sinuses glandular. Corolla pale yellow, subsalverform, glabrous outside; tube ca. 18 mm, glabrous inside; lobes long narrowly triangular, ca. 1.5 mm, dorsally with wing ca. 1 mm wide with very short horn at top, apex rostrate. Capsules not seen. Fl. Oct.

● Shady places in forests in limestone regions. Guangxi (Nandan).

In the protologue and FRPS (71(1): 162. 1999), H. S. Lo detailed both long-styled and short-styled flowers, with similar corollas but differing in anther and stigma positions (in the middle of the corolla tube vs. the throat, respectively and correspondingly).