Centaurea collina subsp. collina

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 : 264

(a) Subsp. collina :

Leaf-segments linear, entire. Appendages of outer bracts brown, more or less patent, the spine 5-13 mm. Florets pale yellow. Corse, S. France, N. W. Italy.