Branched perennial with stems velvety hairy. Flowers small, with white petals interspersed with green sepals about the same length, and 10 or more stamens. Blooms May–October. Basal leaves long-stemmed, often pinnate (like a feather); stem leaves alternate, usually with 3 leaflets with oblong, lobed, and toothed divisions. Uppermost leaves often undivided, sessile. Stipules occur at all nodes. Fruit a burrlike mass of seeds with pointed receptacles and the numerous protruding dried styles.
Similar species: Spring avens, or early water avens (G. vernum) has yellow or cream-colored flowers, blooms April–June, and is most common in moist places in eastern and southern Missouri. Rough avens (G. laciniatum) has white flowers with the petals mostly shorter than the calyx lobes. It is found only in northern and central Missouri. Prairie smoke (G. triflorum) has large, plumelike fruiting heads. Pale avens (G. virginianum) is rare and scattered in southern Missouri.