Flower:

Flowers are at the end of branching stems and arising from leaf axils in the upper part of the plant. Individual flowers are ¼ to 1/3 inch across, with 5 (sometimes 3 or 4) shiny yellow petals, a ring of yellow stamens around a green center, and 5 (sometimes 3 or 4) yellow-green sepals. The sepals spread back away from the flower with maturity and are about as long as the petals, but may be a bit longer or shorter. 

Leaves and stem:

There are both basal leaves and alternate stem leaves. Basal leaves are up to 3 inches long and wide, on long stalks and shallowly lobed in 3 to 5 main parts. Stem leaves are more deeply lobed with the main lobes further divided, generally kidney-shaped in outline, becoming smaller on shorter stalks and narrower lobes as they ascend the stem; those near the flowers are stalkless. Stems are hollow. The plant is hairless, or nearly so.

Fruit:

The flower center expands to an elliptic or cylindrical seed head up to ½ inch long. Seeds have a minute beak that is usually straight; surfaces are smooth or finely wrinkled depending on variety,

Notes:

There are several buttercup species with small yellow flowers. The habitat, leaf shape, and overall plant size are usually the easiest ways to distinguish them. Cursed Crowfoot is fairly common and can be weedy. The stem oozes a sap that may cause blisters, which is probably where the “cursed” name originates. There are 2 varieties in North America, both found in Minnesota: var. multifidus is most common and has smooth seeds, var. sceleratus has seeds with a finely wrinkled surface.