Centaurea

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 : 281

Sect. CYLiNDRACEA (Hayek) Dostál. Stem herbaceous, the branches not spiny. Leaf-segments not rigid or spiny. Involucre cylindrical; appendages with an erect or patent apical spine which is not spiny or fimbriate at its base, the lower fimbriae free. Florets purple or pink, rarely white or cream.