buttercup, water crowfoot
cosmopolitan, the tropics
Species commonly cultivated
Ranunculus aquatilis L. (Africa, Europe, North America)
R. flagelliformis Sm. (Mexico and South America)
R. flammula L. (North Africa, Europe, North America)
R. limosella Kirk (New Zealand)
R. lingua L. (Asia, Europe)
R. peltatus Schrank
Ranunculus ficaria L., R. repens L., and R. acris L. are introduced into the United States from Europe.
Ranunculus acris is listed as a noxious weed in Montana (United States).
Annual or perennial. Stem variable, compact or elongate, erect or ascending; submerged aquatic species usually with elongate stems while emergent species often compact. Leaves highly variable, in a rosette or cauline, alternate or whorled; leaf blade linear to orbicular, lobed to palmately divided; segments of submerged leaves capillary. Inflorescence solitary or flowers in a cymose panicle. Flowers actinomorphic; sepals 5; petals (nectar leaves) 5, distinctive, rounded, yellow or white. Dispersal of fruit (nutlets) by water, possibly by animals.
pond margins, along streams, often on wet ground
Ranunculus consists of 400 species, about 35 of which are aquatic.