Carduus candicans subsp. candicans

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 : 228

(a) Subsp. candicans :

Outer and middle involucral bracts in 3-5 rows, the mid-vein raised in its distal |; inner bracts scabrid on margins. Throughout the range of the species, except parts of the south-east.