Description from Flora of China
Swertia mileensis T. N. Ho & W. L. Shi.
Annuals 15-45 cm tall. Roots yellow, fibrous. Stems basally erect, subquadrangular, branched throughout so whole plant is pyramidal. Leaves sessile, linear, narrowly oblong, or lanceolate, 0.4-4 cm × 2-4 mm, base narrowed, apex acute, veins 3. Flowers solitary, terminal, 4merous. Pedicel erect, 0.4-3 cm, terete, base with a pair of bractlets. Calyx tube 1-2 mm; lobes linear-lanceolate, 6-10 mm, apex acute, primary veins 1-3. Corolla pale blue, ca. 1 cm in diam., tube 1-2 mm; lobes oblong to ovate-lanceolate, 7-12 mm, apex acute and apiculate. Nectaries 2 per corolla lobe, yellow-green, pocket-shaped with an orbicular scale and many minutely papillose short fimbriae. Filaments 4.5-6 mm; anthers blue, ellipsoid, 2-2.5 mm. Style short, distinct; stigma lobes capitate. Capsules ovoid-ellipsoid to ellipsoid, to 1 cm. Seeds dark brown, ovoid, ca. 0.6 mm in diam. Fl. and fr. Sep-Nov.
* Grasslands on hillsides; 1300-1700 m. S Yunnan.