Colutea is an Old World genus of 28 species, mainly distributed in Eurasia and northeastern Africa. Some species are rather frequently planted as ornamentals in Europe (Cullen 1995, Roloff & Bärtels 2006) but only the two taxa treated in this account seem to be widespread in cultivation.
- Corolla orange to brownish red. Keel 15-16 mm long, weakly beaked === 2. Colutea x media
- Corolla yellow (often with reddish veins). Keel 16-20 mm long, not beaked === 1. C. arborescens
Browicz K. (1963) The genus Colutea L. A monograph. Monograph. Bot. 14 : 1-136.
Browicz K. (1967) A supplement to the monograph of the genus Colutea L. Arb. Kornickie Roczn 12: 33-43.
Cullen J. (1995) Colutea. In: Cullen J. & al. (eds.), The European Garden Flora, vol. 4. Cambridge University Press, Cambridge: 502-503.
Roloff A. & Bärtels A. (2006) Flora der Gehölze (2e Auflage). Ulmer, Stuttgart: 844 p.