Description from
Flora of China
Swertia dilatata C. B. Clarke.
Annuals 80-120 cm tall. Roots yellow, fibrous. Stems erect, 1.5-4 mm in diam., striate, branched. Basal leaves withered at anthesis. Stem leaves subsessile, lanceolate, 2-5.5 cm × 4-14 mm, abaxially puberulent, adaxially sometimes glabrous, base obtuse, margin ciliolate, apex acuminate; veins 1-3, prominent. Inflorescences panicles of cymes, many flowered, spreading, to 70 cm. Pedicel erect, 0.6-1.5 cm, terete, striate. Flower 5merous. Calyx tube 1-1.5 mm; lobes ovate-lanceolate, 6-10 × 2-5 mm, slightly unequal, papillate, margin ciliolate, apex acuminate; veins 1-3, indistinct. Corolla pale yellow-green, with 2 blackish purple spots above each nectary, tube 1-1.5 mm; lobes ovate, 6-8 mm, apex acute. Nectaries 1 per corolla lobe, horseshoe-shaped, naked. Filaments 4-5 mm, basally much enlarged but free; anthers purple, ellipsoid, 1-1.5 mm. Style 2.5-3.5 mm, slender; stigma lobes capitate. Capsules ovoid, 8-10 mm. Seeds pale yellow, ellipsoid; seed coat smooth. Fl. and fr. Aug-Sep.
Scrub slopes, forests; 2800-3300 m. S and SW Xizang, Yunnan [Bhutan, India, Kashmir, Myanmar, Nepal, Sikkim].