Scientific name

Caltha L.

Common names

marsh marigold, king's cup, may blob, meadow-bright



Could be confused with

Nymphoides, Ranunculus

Native distribution

temperate regions of the world

Species commonly cultivated

Caltha leptosepala DC. (North America)

C. natans Pall. ex Georgi. (U.S.)

C. palustris L. (C. polypetala Hochst. ex Lorent) (cosmopolitan)

Adventive distribution

information not available

Weed status

information not available


emergent rosette or creeping stem plant

Brief description

Perennial, herbaceous. Stem creeping or ascending, rhizomatous. Leaves submerged, floating or emergent, in a rosette, alternate; leaf blade simple, lobed or reniform to circular; margin entire or toothed, sometimes upturned basally. Flowers solitary or in loose cymose panicles; actinomorphic; perianth segments in single whorl, 5 or more, yellow or white. Dispersal of seeds by water or unknown.

Natural habitat

wet areas and margins of cool-cold waters, often around snowmelt runoff

Additional comments

Genus consists of ten species found in temperate regions. Some species are recorded as poisonous when eaten. Some species are endangered in the United States.