Geranium sibiricum L.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Annual or short-lived perennial; stems weak, spreading to erect, to 1 m, villous; cauline lvs reniform, 4–7 cm wide, palmately 3–5-cleft, the segments coarsely toothed or lobed, chiefly above the middle; peduncles with 1 or occasionally 2 fls, on villous pedicels; sep villous, 5–7 mm, shortly awned; pet upcurved, ± emarginate, scarcely surpassing the sep; mature fr, including the cal, 15–20 mm, the stylar beak ca 1 mm or less, the carpel-bodies finely pubescent on the sides, pilose on the back. Native of Asia and e. Russia, intr. here and there in our range. Aug., Sept.