Viper's Bugloss

Viper's Bugloss (Echium vulgare) is a short to medium perennial with rough, hairy, lanceolate leaves. The flowers start pink and turn vivid blue and are 15–20 mm in a branched spike, with all the stamens protruding. It flowers between May and September. It is found in dry, bare and waste places in Britain and Northen Europe.

Reference

The Wild Flowers of Britain and Northern Europe. Fitter, R. & A., Collins 1974.