Stems branching, I to 2 feet long, or becoming longer in summer, ascending, the later branches procumbent and often rooting at the nodes. Roots simply fibrous; stems glabrous or pubescent. Leaves large, petioled, three-divided, the divisions mostly stalked, usually cuneate at the base, cleft into broad lobes; petioles of the lower leaves sometimes a foot long. Flowers bright yellow, 1 to 1 ¼ inches broad; petals five, obovate, twice as long as the spreading sepals. Stamens numerous. Fruit a globose or oval head of flat, strongly margined achenes, each achene tipped by the subulate, persistent, sword-shaped style.
Marshes, swamps, ditches and low meadows, New Brunswick to Manitoba, Georgia and Kansas. Flowering from April to July.
Memoir 15 N. Y. State Museum
Swamp Or Marsh Buttercup - Ranunculus septentrionalis