Ranunculus japonicus

Ranunculus japonicus is a perennial herb in the Ranunculaceae family, native to East Asia including China, Japan, Korea, and the Russian Far East. The plant reaches 20-65 cm in height, with erect, pubescent, branched stems arising from a short rhizome bearing fibrous roots. Basal leaves are long-petiolate, palmately three- to five-lobed with crenate-dentate margins, while stem leaves are sessile and more deeply divided into narrow lobes. The bright yellow, glossy flowers are 1.5-2.2 cm across, with five spreading petals and numerous stamens, borne singly on long peduncles. Fruits are clusters of glabrous achenes with short, hooked beaks aggregated into globose heads. It inhabits moist meadows, stream banks, and wet grasslands from lowlands to mid-elevations. Like other buttercups, it contains the irritant glycoside ranunculin, which hydrolyzes to the vesicant protoanemonin in fresh tissue, making the raw plant toxic and skin-blistering.