Anthyllis vulneraria shows an appreciable variation in the colour of the corolla which ranges from pale yellow to a deep purplish red. Also the calyx often has purple teeth. Most of the subspecies of A. vulneraria (16 out of 24) occur in the Mediterranean area, more particularly in the N. and W. parts. About the moiety of these subspecies has purple or reddish flowers; the other half predominantly yellow or yellowish ones. In central Europe 4 subspecies with yellow corollas occur; red-flowered variants are rare. In N. Europe also 4 subspecies are found of which one has a red-flowered variety: A. vulneraria ssp. vulneraria var. coccinea (Cullen 1968). The red floral colour is predominantly found in the Mediterranean area. According to Becker (1912) the red-flowered populations are mostly encountered in drier and warmer climates; the yellow-flowered ones being more dominant in the colder and moister regions.

Acta botanica neerlandica

CC BY 3.0 NL ("Naamsvermelding")

Koninklijke Nederlandse Botanische Vereniging

A.A. Sterk, P. de Vlaming, & A.C. Bolsman-Louwen. (1977). Some observations on the anthocyanins in the flowers of Anthyllis vulneraria L. (Leguminosae – Fabaceae). Acta botanica neerlandica, 26(4), 349–351.