叉序草 cha xu cao

Justicia collina T. Anderson, J. Linn. Soc., Bot. 9: 515. 1867; Chingiacanthus patulus Handel-Mazzetti; Dianthera collina (T. Anderson) C. B. Clarke; D. sinensis W. W. Smith.

Herbs 40-100 cm tall. Stems prostrate and rooting at base but apically erect, terete, slender, slightly puberulent when young, later glabrescent. Petiole 1-3 cm, brownish pubescent; leaf blade ovate to ovate-elliptic, 3.5-11 × 2-4.8 cm, abaxially sparsely puberulent especially along veins, adaxially glabrous, secondary veins 5-7 on each side of midvein, base cuneate or on uppermost leaves rounded, margin ± entire, apex acuminate. Inflorescences terminal or axillary from upper leaf axils, panicles, 5-18 × 3-10 cm; rachis gland-tipped puberulent or subglabrous with few sessile glands; branches slightly flattened; bracts lanceolate, 1.5-2 × ca. 0.5 mm, glabrous or slightly gland-tipped pubescent. Calyx 5-8 mm; lobes subulate, glabrous or gland-tipped puberulent. Corolla white with purplish dots, 1.7-4.5 cm, outside glabrous; tube basally cylindric for ca. 1/3 of its length then gradually widening into a funnel-shaped throat; lips 8-10 mm; lobes of lower lip oblong-elliptic, 3-6 mm, unequal with lateral 2 narrower. Staminal filaments 4-10 mm, glabrous; anther thecae to 4.5 mm, equal, parallel, overlapping for ca. 1/2 their length or more. Ovary glabrous; style glabrous. Capsule 1-1.4 cm, glabrous. Seeds coarsely corrugated with irregular ridges and often with minute acute protuberances. Fl. Aug-Nov.

Evergreen broad-leaved forests, wetlands by streams; 300-2200 m. Guangdong, Guangxi, Hunan, Jiangxi, Xizang, Yunnan [Bhutan, India, Thailand].