Ranunculus flammula

Perennial herb.

10–40 cm high.

The stem is ascending, rarely erect, typically rooting only at basal nodes, and few-branched. The internodes are somewhat straight. The first internode is typically at least 2 mm thick and glabrate.

The basal leaves are long-petiolate (even 15 cm or more on aquatic forms). The lamina is 1–6 cm long, ovate – lanceolate, simple, entire or toothed. The stem leaves are short-petiolate and the distal leaves are sessile, linearly lanceolate and typically entire.

The flowers are solitary or in clusters of few. The pedicels are sulcate. The corolla is yellow and typically 8–18 mm wide. The length of the calyx is half of the length of the corolla. The calyx is caducous.

The achenes are 1.7–2.3 mm long, glabrous, and the beak is 0.2–0.3 mm long.