This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Anemone virginiana L. Sp. Pl. 540. 1753. A. riparia Fernald, Rhodora 1: 51. 1899.
Hairy, 2°-3° high, stout, branching at the involucre, the lateral peduncles bearing secondary involucres. Basal leaves long-petioled, broader than long, 3-parted, the divisions broadly cuneate-oblong, variously cleft and divided into acute serrate lobes; those of both primary and secondary involucres similar, on petioles l'-2' long; sepals generally 5, white or greenish, acute or obtuse; flowers 9"-18" broad; head of fruit oblong to subcylindric, 9"-12" long; achenes compressed, woolly, tipped by the spreading or ascending subulate styles.
In woods, Nova Scotia to South Carolina, Kansas, Alberta and Arkansas. Consists of several races, differing in size and color of flower, shape of fruit and in the styles. Tumble-weed. Thimble-weed. June-Aug.
Anemone canadensis L. Syst. Ed. 12, 3: App. 231. 1768.
Anemone pennsylvanica L. Mant. 2: 247. 1771.
Rather stout, 1°-2° high, somewhat hairy, especially on the lower surfaces of the leaves, branching at the involucre. Basal leaves long-petioled, broader than long, 3-5-parted, the divisions broad, oblong, acute, variously cleft and toothed, those of both primary and secondary involucres similar, sessile; sepals white, oblong, obtuse; flower 1'-1 1/2' broad; head of fruit globose; achenes flat, nearly orbicular, pubescent, tipped with the stout persistent style, which is about their own length.
Low grounds, Labrador to Assiniboia, Massachusetts, Maryland, Illinois, Kansas and Colorado. A. dichotoma L., to which this has been referred, is a Siberian species with glabrous ovate achenes. Crowfoot. Round-headed anemone. May-Aug.
Anemone Richardsonii Hook. Fl. Bor. Am. 1: 6. 1829.
Low, slender, pubescent, 2'-12' high from slender root-stocks. Basal leaves reniform, slender-petioled, 3-5-parted, the lobes acute, broadly oblong, dentate or crenate; those of the involucre similar, sessile; flower solitary, 9" broad, yellow; sepals about 6, oblong; head of fruit depressed-spherical; achenes nearly glabrous, compressed, ovate-oblong, reflexed, tipped with a hooked persistent style of about their own length.
8. Anemone quinquefòlia L. Wind-flower. Snowdrops. Fie. 1887.
Anemone quinquefolia L. Sp. Pl. 541. 1753.
Anemone nemorosa var. quinquefolia A. Gray, Man. Ed. 5, 38. 1867.
Low, simple, nearly glabrous, 4'-9' high, from horizontal rootstocks. Basal leaves long-petioled, appearing later than the flowering stem, 5-parted, the divisions oblong, cuneate, dentate; those of the involucre on slender petioles about 9" long, 3-5-parted, the divisions 1 1/2' long, acute, variously cut and lobed; flower solitary, 1' broad; sepals 4-9, obovate or oval, white, or purplish without; head of fruit globose, inclined; achenes pubescent, oblong, tipped with the hooked styles.
In low woods, Nova Scotia to Georgia, western Ontario, Minnesota and Tennessee. Ascends to 3500 ft. in Virginia. Readily distinguishable from the European A. nemorosa L., which is sometimes cultivated in our area and reported as escaped in Massachusetts, by its slender habit, slender petioles, less lobed divisions of the involucral leaves, paler green foliage, more slender root-stocks, and smaller flowers. Wood-flower. May-flower. Nimble-weed. Wood-anemone. Wild cucumber. April-June.