Eastern False Rue-Anemone
[Isopyrum biternatum (Raf.) Torr. & A. Gray]
Stems 10-40 cm, weakly rhizomatous; roots fibrous. Leaves: leaflets irregularly 2-3-lobed, lobes sometimes with 1-3 secondary lobes, apex rounded, glandular-apiculate; surfaces abaxially glabrous. Inflorescences axillary, flowers solitary or loosely grouped in 2-4-flowered leafy racemes; peduncle not strongly clavate. Flowers: sepals 5.5-13.5 × 3.5-8.5 mm; stamens 25-50; filaments filiform to club-shaped, 1.8-5.8 mm. Follicles sessile, upright to widely divergent; body widely elliptic to widely obovate, 3.5-6.5 mm, gradually contracted into style beak; beak 1.7-3 mm. Seeds 2.1-2.7 mm, minutely pubescent. 2 n = 14. Flowering spring. Moist deciduous woods of valleys, flood plains, and ravine bottoms, occasionally in open pastures, often on limey soils; 25-1000 m; Ont.; Ala., Ark., Fla., Ill., Ind., Iowa, Kans., Ky., Mich., Minn., Miss., Mo., N.Y., N.C., Ohio, Okla., S.C., S.Dak., Tenn., Va., W.Va., Wis. Enemion biternatum has been mistaken for the superficially similar Thalictrum thalictroides because of its white flowers and compound Thalictrum -like leaves. Enemion biternatum is easily distinguished, however, by its few-seeded follicles and deeply lobed leaves with glandular-apiculate apices. Thalictrum thalictroides , on the other hand, is characterized by having achenes and somewhat crenate leaves with notched apices.
From Flora of Indiana (1940) by Charles C. Deam
Infrequent to common in moist, rich woods throughout the state. Probably absent from a few of the northwestern counties. It prefers the beech and sugar maple type of woods.
Indiana Coefficient of Conservatism: C = 5
Wetland Indicator Status: FAC
Roots with many small, tuber-like thickenings; stems slender, 1-4 dm; basal lvs long-petioled, 2-3-ternate; cauline lvs smaller, less petiolate and less dissected; lfls broadly obovate, 3-lobed; fls white, 1.5-2 cm wide; follicles mostly 4, semi-ovoid, compressed, divergent; 2n=14. Moist woods; w. N.Y. and s. Ont. to Minn., s. to the piedmont of Va. and the Carolinas, and to w. Fla. and Ark. Apr., May. (Enemion b.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
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