Centranthus calcitrapae, (L.) Dufresne

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 : 56

7. C. calcitrapae (L.) Dufresne , Hist. Nat. Méd. Fam. Valér. 39 (1811).

Stems 4-40(-75) cm, simple or branched. Leaves 10-90 x 6-40 mm, orbicular to obovate in outline, the lobes entire to incise-serrate. Partial inflorescences several, capitate. Corolla pink or white, gibbous or shortly spurred with the spur not exceeding the base of the tube; tube 1—2(—3) mm. 2л = 32. Waste places. S. Europe. Az BI Co Cr Ga Gr Hs It Ju Lu Rs (K) Sa Si.

Very variable in characters of leaf and flower, but there is little correlation with geography. Two subspecies are recognized.