1. Knoxia roxburghii (Sprengel) M. A. Rau, Bull. Bot. Surv. India. 10(Suppl. 2): 40. 1969.
红大戟 hong da ji
Spermacoce roxburghii Sprengel, Syst. Veg. 1: 404. 1824; Knoxia valerianoides Thorel ex Pitard.
Erect herbs, 30-70 cm tall; root sometimes purple, rather enlarged, fleshy, fusiform; branches subquadrate, becoming channeled, puberulent or villosulous becoming glabrescent. Leaves sessile or subsessile, opposite or often ternate; blade drying papery, lanceolate or oblong-lanceolate, 7-10 × 3-5 cm, both surfaces glabrescent or usually hispidulous to pilosulous or strigillose at least on principal veins, base acute to rounded, apex obtuse to acuminate; secondary veins 5-7 pairs, usually indistinct; stipules persistent, shortly fused to petioles or united around stem, linear to narrowly triangular or sometimes shortly to deeply 2- or 3-lobed, 8-10 mm, villosulous to glabrescent, acute. Inflorescences congested-cymose to subcapitate, puberulent or villosulous to glabrescent, ebracteate; peduncles 3-12 cm; dense flower groups 1-1.5 × 1-2.5 cm, borne singly or 3-5 on cymose axes; pedicels 0.5-1 mm. Calyx glabrescent; ovary portion ellipsoid, ca. 0.5 mm; limb deeply lobed; lobes triangular, 0.1-0.5 mm, often unequal on an individual flower. Corolla red, purplish red, or white, salverform or tubular, externally densely villosulous or glabrous; tube 3-4 mm; lobes triangular to ovate, ca. 1 mm. Schizocarps oblong-ellipsoid, somewhat didymous, laterally somewhat flattened, ca. 1.5 mm; mericarps separating from each other and carpophore; carpophore persistent, linear, ca. 1.3 mm.
Grasslands on mountain slopes. Fujian, Guangdong, Guangxi, Hainan, Yunnan, Zhejiang [Cambodia, India, Myanmar, Nepal, Thailand].
Bhattacharjee and Deb (J. Econ. Taxon. Bot. 6(1): 85. 1985) apparently included the Chinese plants within their circumscription of Knoxia roxburghii var. brunonis (Wallich ex G. Don) R. Bhattacharjee & Deb, which falls into K. roxburghii as circumscribed by Puff and Robbrecht (Bot. Jahrb. Syst. 110: 511-558. 1989). This name is based on Spermacoce brunonis Wallich ex G. Don (Gen. Hist. 3: 621. 1834). W. C. Ko (in FRPS 71(2): 4. 1999, as K. valerianoides) described the corollas of this species as salverform and densely pubescent externally; however, the corollas of Thai plants of this species are more tubular and are glabrous externally.