Centaurium erythraea subsp. erythraea

Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. & Webb, D. A., 1972, Flora Europaea. Volume 3. Diapensiacea to Myoporaceae, Cambridge: Cambridge University Press : 58

(a) Subsp. erythraea (C. umbellatum auct., Erythraea centaurium auct., non (L.) Pers., E. capitata Willd. ): Middle cauline leaves usually narrowly lanceolate or narrowly elliptical; calyx usually c. £ as long as the corolla-tube; stamens inserted at the apex or at the base ( var. capitatum (Willd.) Melderis ) of the corolla-tube. In = 40. Almost throughout the range o f the species.

Hybrids with 5 (2zz = 40, 40^48), with 11 and with 12 (2« = 40) occur.

Variants with the calyx j as long to almost as long as the corolla-tube, occur in C. and S.E. Europe.