Sp. Pl. 1: 547. 1753.
Herbs, perennial, stout-rhizomatous. Stems 1-4, 5-35 cm at anthesis (10-40 cm at fruiting time). Leaves: basal leaves scalelike, 1cm, sessile; proximal cauline leaves with sheathlike petiole base, distal leaves short-petiolate to sessile; leaf-blade 1-2-pinnatisect. Flowers 4-8 cm diam.; sepals appressed to petals, ovate-elliptic to obovate, margins and abaxial surface villous, apex slightly crenulate to ±erose; petals 10-20, spreading, yellow, without basal blotch, plane, 25-35 mm, 1.5 times length of calyx, apex erose or irregularly crenulate; stamens ca. 80; anthers yellow; pistils 40-50. Heads of achenes globose to ovoid, 15-20 × 12-15 mm; pedicels hidden among dense leaves; achenes pubescent, 3.5-5.5 mm, transverse flange absent, basal tooth absent, adaxial margin very short (1 mm), straight, abaxial margin strongly gibbous; beak strongly recurved against abaxial surface, 0.5-1 mm.
Phenology: Flowering spring (Apr–May).
Habitat: Roadsides and sites adjacent to gardens
Introduced; N.Y., native to Eurasia
Adonis vernalis occasionally escapes from cultivation as an ornamental. It is much less frequently encountered in the flora than the other two species of Adonis.