Description from Flora of China
Herbs perennial, ± purplish. Roots fibrous. Sterile shoots suberect, slender, 2-4 cm, leafy. Flowering stems several, suberect, tufted, 5-12(-22) cm. Leaves 3- or 4-verticillate; leaf blade broadly linear to lanceolate, 6-11 × 1-1.5 mm, base shortly spurred, apex obtuse. Cyme scorpioid, many flowered; bracts suboblong, ca. 5 mm, apex obtuse. Flowers sessile, unequally 5-merous. Sepals broadly linear to suboblong, ca. 2.5 × 0.8 mm, base spurless, apex obtuse. Petals yellow, lanceolate, ca. 5 × 1.2 mm, apex mucronate. Stamens 10; antesepalous ones ca. 4 mm; antepetalous ones ca. 3 mm, inserted 0.5-0.8 mm from petal base. Nectar scales subquadrangular, ca. 0.5 × 0.4 mm, apex emarginate. Carpels ca. 5 mm, base connate for ca. 1 mm, apex divergent. Styles ca. 1 mm. Follicles many seeded. Seeds subovoid, ca. 0.5 mm, minutely mammillate. Fl. Apr-May, fr. May-Jun.
* Shady moist rocks in open places; ca. 200 m. Anhui, Jiangsu, Zhejiang.