Swertia tetraptera Maxim.

Annuals 5-30 cm tall. Roots yellow, fibrous. Stems 1 to few, robust, erect, 2-3.5 mm in diam., subquadrangular, with larger flowers, and numerous weak branches from base, with flowers 1/4-1/3 as large as those of robust stems. Basal and lower stem leaves withered at anthesis; petiole 1-5 cm; leaf blade oblong to elliptic, 0.9-3 × (0.8-)1-1.8 cm, thin herbaceous, base narrowed, apex obtuse, veins 3 and abaxially prominent. Middle to upper stem leaves sessile, ovate-lanceolate, 1.5-4 × 1-1.5 cm, base rounded and subamplexicaul, apex acute; veins 3-5, abaxially prominent. Inflorescences panicles of cymes, many flowered, spreading. Flowers 4merous. Pedicel 0.5-6 cm, slender. Calyx lobes basally narrowed, apex acute, veins 3. Corolla pale yellow-green, sometimes tinged purple; lobes apically obtuse and erose. Nectaries 2 per corolla lobe, oblong, double door-shaped, each with a very narrow scale and few irregular divisions. Anthers yellow, ellipsoid. Style indistinct; stigma lobes capitate. Seeds pale yellow, subglobose, almost smooth. Flowers on robust stems: calyx tube 0.5-1 mm; lobes lanceolate to ovate-lanceolate, 6-8 mm. Corolla tube 0.5-1 mm; lobes ovate, 0.9-1.2 cm. Filaments 2-3.5 mm; anthers 0.5-1.5 mm. Capsules ovoid-ellipsoid, 1-1.4 cm. Seeds 1-1.2 mm. Flowers on weak branches: calyx tube 0.3-0.5 mm; lobes broadly ovate, 1.5-4 mm. Corolla tube 0.3-0.5 mm; lobes ovate, 2.5-5 mm. Filaments 2-3.5 mm; anthers 0.5-1.5 mm. Capsules broadly ovoid to subglobose, 4-5 mm. Seeds less than 0.1 mm. Fl. and fr. Jul-Sep.

Gansu, Qinghai, Sichuan, Xizang.

* Beside streams, wet slopes, scrub, scattered forests; 2000-4000 m.

Swertia dimorpha Batalin; S. pusilla Diels.