Carduus pycnocephalus subsp. pycnocephalus

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 : 231

(a) Subsp. pycnocephalus :

Apices of involucral bracts 2-3 mm wide, erecto-patent, ovate-lanceolate, more or less contracted into a spine, with the mid-vein raised in the distal |. Throughout the range of the species except S. Greece and U.S.S.R.