Green Alkanet (Pentaglottis sempervirens) has become a widespread wildflower and for that reason is often regarded as a weed. It has deep tap roots that make it difficult to eradicate and self-seeds readily. Of Mediterranean origins P. sempervirens may have been introduced to these shores as a dye plant; the roots are said to yield a henna shade of red.
 I am very happy to see it colonising rough ground and neglected areas. The haze of blue flowers attracts bees aplenty.