Description from Flora of China
Herbs, perennial, 80-150 cm tall. Stems glabrous, simple or branched. Leaves alternate, subsessile or shortly petiolate, ± falcate-ovate to falcate-lanceolate, 6-15 × 1.5-4 cm, thinly papery, glabrous, base broadly cuneate, margin ciliate-denticulate, apex caudate-acuminate. Racemes terminal, 15-40 cm, lax, lower bracts conformable with leaves, upper ones narrowed to linear, longer than flowers, margin ciliate-denticulate; pedicels compressed, 3-5 mm, with 2 subulate bracteoles at middle. Hypanthium semiellipsoid, 3-4 mm, glabrous; calyx lobes filiform, 13-21 × less than 1 mm, margin entire, spreading at fruiting. Corolla reddish, 12-17 mm; limb 2-lipped; upper lobes ascending, linear-lanceolate, as long as tube, inside villous; lower ones lanceolate-elliptic, ca. 2/3 as long as tube, inside densely villous, spreading. Stamens densely villous at base, connate into tube above base; filament tube glabrous; anther tube ca. 4 mm, back sparsely villous, only lower anthers barbate at top. Capsule erect, subglobose, 5-6 mm wide, glabrous. Seeds oblong, slightly compressed, ca. 0.6 mm, foveolate. Fl. and fr. Aug-Oct.
● Ravines, roadsides, by streams or wet places in forests; below 1000 m. Fujian, Guangdong, Hubei (Badong, Zigui), Hunan (Yizhang), Jiangsu (Suzhou), S and W Jiangxi, Zhejiang (Longquan).