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

Family: Ranunculaceae

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.

Habit: 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 snow melt 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.