Branching annual to 1 m; lvs sparsely hispidulous, pinnately dissected, the ultimate segments 3-8 mm; umbels lf-opposed, lax, with 3-5 rays 1-2 cm; bractlets lance-ovate, aristate, 2-3 mm; pedicels elongating and becoming thicker than the rays in fr; fr ovoid, 3-4 mm, the body covered with short, thick, uncinate prickles, the short stout beak unarmed; 2n=14. Native of Europe, intr. here and there in the U.S. June, July. (A. scandicina)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
