Centranthus ruber subsp. ruber

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 : 55

(a) Subsp. ruber :

Leaves ovate to lanceolate, the uppermost often dentate, acute. Corolla-tube (5-)7-10mm; spur (2-)4-7 (-9) mm. 2л = 32. Almost throughout the range of the species.