There are 335 ranunculaceae (buttercup) species in the US, in 30 genera; the largest groupings are anemone, aquilegia, clematis, delphinium, ranunculus and thalictrum. Most species are herbs; a few are vines, small shrubs or aquatic plants. Leaves are produced at the base and along the stems (usually alternate); they may be simple or compound, commonly with lobed margins.

Flower components are variable; sepals are commonly in the range 3 to 6 (but sometimes up to 20), petals zero to many, stamens five to many, and pistils one to many. Plants with no petals have petal-like sepals instead. Flowers can be bilaterally or radially symmetric. The inflorescence is usually solitary, but can be clustered. Ranunculaceae species are found all over the US, but are most numerous in temperate areas.