Swertia patula H. Smith

Annuals 5-15 cm tall. Roots yellow, fibrous. Stems ascending, striate, branched from base so whole plant is somewhat cespitose. Basal leaves withered at anthesis; petiole short; leaf blade oblanceolate to spatulate, 1-2.5 cm × 2-5 mm, base narrowed, apex obtuse, veins 1-3. Stem leaf blades linear to linear-lanceolate, 0.7-1.8 cm × 1.5-3 mm, base narrowed, apex acuminate, midvein distinct. Inflorescences usually reduced to a single flower, sometimes racemelike. Flowers 4merous. Pedicel erect, 1.5-2 cm, terete, base with a pair of bractlets. Calyx tube 1-2 mm; lobes narrowly linear-lanceolate, 1-1.8 cm, apex acute and apiculate, midvein distinct. Corolla white, rarely pale purple, with purple veins, to 2.5 cm in diam., tube 1-2 mm; lobes spatulate-oblong to elliptic, 1.2-1.7 cm, base narrowed, apex rounded and mucronate. Nectaries 2 per corolla lobe, yellow-green, pocket-shaped with an orbicular scale, glabrous or with many tomentose short fimbriae. Filaments 6-8 mm; anthers blue, ellipsoid, ca. 2 mm. Ovary ovoid-ellipsoid, 6-7 mm. Style short, distinct; stigma lobes capitate. Fl. Jul-Sep.

SW Sichuan, NW Yunnan.

* Gravel slopes, scrub, forest margins, forests; 1400-3400 m.

Swertia patula là một loài thực vật có hoa trong họ Long đởm. Loài này được Harry Sm. miêu tả khoa học đầu tiên năm 1936.

开展獐牙菜（学名：Swertia patula），为龙胆科獐牙菜属下的一个植物种。