Description from Flora of China
Razumovia tranquebarica Sprengel, Mant. Prim. Fl. Hal. 45. 1807; Centranthera humifusa Wallich ex Bentham; C. tonkinensis Bonati.
Herbs, slender, basally hirsute, apically subglabrous. Stems erect or prostrate, branched from base; branches slender, mostly diffuse and ascending, dense, fascicled, 5-30 cm. Leaves opposite, rarely alternate below, sessile, linear-lanceolate, usually 0.8-2.5 cm X 2-3 mm, glabrous or midrib with scabrous scalelike bulges on both surfaces or abaxially short hairy, margin entire and slightly revolute, apex acuminate. Bracts longer than corolla. Calyx ovate, ca. 3.5 mm at anthesis, to 5.5 mm in fruit, hispidulous. Corolla yellow, brown striate, ca. 9 mm; throat densely black punctate; lower lip lobes suboblong, ca. 2 mm wide, apex somewhat sharp; upper lip ca. 3 mm, lobes suborbicular and ca. 2 mm in diam. Anterior stamens 3-5 mm; filaments densely white lanose-villous. Posterior stamens 2-4 mm; filaments apically villous. Ovary oblong, ca. 3 X 2.5 cm, glabrous. Capsule subglobose, 4-5 X ca. 4 mm, as long as persistent calyx. Seeds yellow, cylindric-conical, ca. 1 mm; seed coat reticulate. Fl. and fr. Jul-Oct.
Grassland on mountain slopes, trailsides, sandy slopes near ocean; low elevations. Fujian (Xiamen Shi), C Guangdong, Guangxi, Hainan [Cambodia, India, Laos, Malaysia, Sri Lanka, Thailand, Vietnam].