Description from Flora of China
Buchnera angustifolia D. Don, Prodr. Fl. Nepal. 91. 1825.
Annuals, 15-45 cm tall. Stems erect, subquadrangular, simple, rarely apically branched, hispidulous. Leaves sessile, linear, 1.5-3.5 cm X 1-2 mm, lower ones smaller, scabrous hairy. Spikes 3- to numerous flowered, 3-15 cm; bracts similar to leaves in shape and size. Pedicel less than 2 mm. Bracteoles less that 1 mm, linear. Calyx 9-10 mm, 15-ribbed, hispidulous along ribs; lobes almost as long as tube, subulate. Corolla white, 1.2-1.5 cm; tube ca. 2 cm X 1 mm, apically curved forward; limb 4-6 mm; lower lip lobes 4-6 X 3-4 mm. Capsule obovoid-oblong, ca. 4.5 X 3 mm. Seeds brown, minute. Fl. Sep-Dec.
Grassy places; low elevations. Hainan (Dongfang Xian) [Bhutan, India, Myanmar, Nepal, Sri Lanka, Vietnam].