Malva sylvestris L.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Erect biennial, 4–10 dm, hirtellous to glabrate; lvs orbicular or reniform in outline, shallowly 3–7-lobed, the lobes broadly rounded, serrate; petioles hairy only or chiefly in a single line on the upper side; bractlets oblong to ovate or obovate; fls fascicled in the upper axils, on pedicels to 5 cm; pet red-purple, 2–2.5 cm; mature carpels rugose-reticulate on the back, glabrous or sparsely hairy; 2n=42. Native of Eurasia, escaped from cult. here and there in our range. June–Aug.