Much branched shrub to 2 m, all branches ending in spiny tips; spine- tipped petioles 5-15 mm, numerous, crowded; fls short-pedicelled along the smaller branches, forming terminal panicles; each fl subtended by 2 ovate bracteoles 2-3 mm; cal loosely villous, 12-16 mm; pet subequal, 15-20 mm; pods 2-4-seeded, 1-2 cm, villous-tomentose, subtended by the persistent cal; 2n=96. Native of Europe, escaped and established in sandy soil and waste places along the coast, from Mass. to Va. June.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.