Ranunculus undosus

Deeply rhizomatous or stoloniferous perennial, mostly 20–50 cm high. Leaves mainly tufted at base; petioles 15–30 cm long; lamina palmatisect, c. orbicular in outline, 3–7 cm diam., the 3 or 5 main segments further divided to c. midway, ultimate segments obtuse or broadly acute, c. 2–6 mm wide, glabrous or with a few scattered hairs beneath. Flowering stems erect, exceeding leaves, 2–8-flowered; sepals 5, spreading, obovate, 5–8 mm long, glabrous or sparsely hairy on back; petals 5–11, narrowly obovate, 8–16 mm long, 3–6 mm wide, yellow, glossy; nectary lobe largely fused to petal, obtuse, truncate or emarginate at apex, forming a narrow pocket, 0.5–1 mm long overall; stamens c. 30–40. Achenes usually 35–60, obovate, 2–2.5 mm long, the sides patterned with c. 6 narrow tuberculate ridges; beak slender, 1.5–2 mm long, erect or recurved; receptacle fairly densely hispid. Flowers Oct.–Apr.