Description from
Flora of China
Ophelia tetrapetala (Pallas) Grossheim; Swertia wilfordii A. Kerner.
Annuals 20-30 cm tall. Roots yellow, stout. Stems erect, 1-2 mm in diam., subquadrangular, branched. Basal leaves withered at anthesis. Stem leaves sessile, ovate-triangular, 1-2.7 × 0.4-1.5 cm, base cordate and subamplexicaul, apex acute, veins 3. Inflorescences panicles of cymes, many flowered, narrow. Flowers 4merous. Pedicel erect, to 2 cm, slender. Calyx tube 1-1.5 mm; lobes linear-lanceolate, 5-7 mm, apex acute, midvein distinct. Corolla purple, 1.2-1.5 cm in diam., tube 1-1.5 mm; lobes elliptic, 6-8 mm, apex acute. Nectaries 2 per corolla lobe, radially elongated, margin raised with many compound fimbriae. Filaments 5-7 mm; anthers ellipsoid, ca. 1 mm. Style indistinct; stigma lobes capitate. Capsules ovoid-ellipsoid, 6-9 mm. Seeds subglobose; seed coat warty. Fl. Aug-Sep.
Meadows; ca. 700 m. Jilin (Changbai Shan) [Japan, Korea, E Russia].