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..
A glabrous perennial herb from a cluster of tuberous-thickened roots, with basal 2-3-ternately compound leaves, those of the involucre similar but sessile, and large terminal umbellate slender-pedicelled white flowers. Sepals thin, petaloid. Petals none. Stamens all anther-bearing. Achenes terete, deeply grooved; stigma sessile, truncate. [Greek, bound together, the plant uniting many of the characters of Anemone and Thalictrum.]
A monotypic genus of eastern North America.
Anemone thalictroides L. Sp. Pl. 542. 1753. Thalictrum anemonoides Michx. Fl. Bor. Am. 1:
322. 1803. Syndesmon thalictroides Hoffmg. Flora 15:
Low, glabrous, 4'-9' high, the flowering stem arising in early spring from the cluster of tuberous roots, the ternately-compound basal leaves appearing later and resembling those of Thalictrum. Leaves of the involucre similar, sessile, the leaflets long-petioled; sepals 5-10, white or pinkish, longer than the stamens; flower 1/2'-1' broad; flowers perfect, umbellate immediately above the involucre; achenes sessile, pointed, 4"-6" long.