Biennial or short-lived (usually monocarpic) perennial to 1 m, pubescent above; bracts and bractlets numerous, 5-8 mm; ovary and fr densely pubescent; umbels 5-10 cm wide; 2n=22. Native of s. Europe, adventive in Md. July-Sept.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.