Xanthium strumarium subsp. italicum, (Moretti) D. Love

Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. & Webb, D. A., 1976, Flora Europaea. Volume 4. Plantaginaceae to Compositae (and Rubiaceae), Cambridge University Press : 143

(b) Subsp. italicum (Moretti) D. Love , Bot. Jour. Linn. Soc. 71: 271 (1976)

( X. californicum E. L. Greene , X. echinatum Murray , X. italicum Moretti , X. strumarium subsp. cavanillesii (Schouw ex Didr.) D. Löve & Dansereau ):

Aromatic. Stems and branches often with violet or brownish lines or dots. Involucre 15-35 x 6-25 mm in fruit, yellow or brown when ripe, covered with stout spines. 2л = 36. Chiefly in the southern part of the range of the species", probably an early introduction from South and North America.

Introgressive hybrid populations between the two subspecies are found and are very variable in appearance, with the involucre small to large with short, fine and dense to coarse and distant spines (X. albinum (Widder) H. Scholz; incl. subsp. riparium (Čelak.) Widder & Wagenitz , X. brasilicum Velloso, X. orientale L. (X. macrocarpum DC.), X. riparium Itz. & Hertsch, X. saccharatum Wallr.)