Blackthorn is a thorny shrub of hedgerows and woodland edges. It bursts into life in March and April when masses of white flowers appear. During the autumn and winter, deep purple fruits (known as ‘sloes’) ripen on its branches. Blackthorn is an important species for all kinds of wildlife, but is especially vital for the rare Black Hairstreak butterfly who lays its eggs in Blackthorn hedges. Here, they overwinter and the caterpillars emerge in spring ready to feed on the Blackthorn.