Centaurea trichocephala subsp. trichocephala

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 : 296

(a) Subsp. trichocephala :

Leaves oblong-lanceolate, sinuately lobed, pale or yellowish-green. Involucre c. 18 x 10 mm, ovoidglobose; appendages c. 10 mm, not covering bracts, dark brown. S. part of U.S.S.R.