Anemone quinquefolia is an early-spring flowering plant in the genus Anemone, native to North America. It is commonly called wood anemone, like Anemone nemorosa, a closely related European species. The American species has been treated as a subspecies of Anemone nemorosa.
It is a perennial herbaceous plant, growing in early spring to 10-30 centimetres (3.9-11.8 in) tall, and dying back down to the root-like rhizomes by mid summer. The rhizomes, that spread just below the earth surface, grow quickly, contributing to its rapid spread in woodland conditions, where it can carpet large areas. The flower is 1-2.5 centimetres (0.39-0.98 in) diameter, with five (occasionally four, or six to nine) petal-like segments (actually tepals). The flowers are white, commonly flushed pinkish.
The leaves are in three parts with deeply lobed lateral leaflets, giving the appearance of five leaflets. The leaf veins are branched and not parallel.
Anemone quinquefolia was named in 1753 by Carl Linnaeus in Species Plantarum. He described it as having leaves with five oval serrated parts; hence the species epithet quinquefolia, meaning "five-leaved".
Anemone quinquefolia is part of a species complex that includes A. grayi, A. lancifolia, A. lyallii, A. oregana and A. piperi.
Anemone quinquefolia has a number of synonyms. These include:
It has also been treated as part of Anemone nemorosa under the names:
The Flora of North America and The Plant List accept only two varieties:
The two are distinguished mainly by the size of the achene (the fruit), the body of which is 2.5-3 mm (0.10-0.12 in) in var. minima as compared to 3-4.5 mm (0.12-0.18 in) in var. quinquefolia.
Other sources accept further varieties, e.g. A. quinquefolia var. bifolia.