Stout, to 2 m, becoming tomentulose-canescent in the infl; principal lvs long-petioled, 1-2 dm, the upper reduced, with sheathing petioles; lfls oblong to elliptic, varying to lanceolate, 2-4 cm, obtuse, finely serrate; umbels 5-15 cm wide, rays 18-35; pedicels and ovary pubescent; fr oblong-elliptic, 4-7 mm, cordate at base, sparsely pubescent along the wingless dorsal ribs; lateral ribs winged; oil-tubes few; seed adherent to the pericarp; 2n=22. Dry woods and thickets; Mass. to Minn., s. to Fla., Miss., and Ark. July-Aug. (A. villosa Walter, not Lag.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
©The New York Botanical Garden. All rights reserved. Used by permission.
From Flora of Indiana (1940) by Charles C. Deam
Infrequent in the unglaciated region on barren wooded slopes and appearing again in the northern counties in a dry, sandy, prairie habitat.