Centaurea aristata subsp. aristata

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 : 276

(d) Subsp. aristata :

Involucre 4-7(-8) mm in diameter, rounded at base; entire part of appendages narrowly triangular, longer than wide, the apical spine 0-8-1 mm, the fimbriae c. 1 mm. Pappus 1 -5-3 mm. Portugal, N. W. Spain.