Centaurea nigrescens subsp. neapolitana

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 : 292

(c) Subsp. neapolitana (Boiss.) Dostál , Bot. Jour. Linn. Soc. 71: 206 (1976)

( C. neapolitana Boiss. ):

Stems simple or with few branches. Cauline leaves narrowly oblong, entire or with few teeth. Involucre c. 10mm in diameter, ovoid-cylindrical; appendages orbicular, brown. C. & S. Italy.