Hundreds of tiny white blossoms emerge in early spring on the bare, thorny branches of blackthorn. These prolific flowers are a common sight in hedgerows and along field edges, the spiky branches often being used as a natural cattle-proof barrier. As one of the earliest blossoms to appear, the multitudes of flowers provide an important source of pollen for foraging spring bees. Foliage arrives later and is itself a food source for many caterpillars, including those of the Brimstone moth and Brown Hairstreak butterfly. With its dark spiny wood and contrasting bright flowers, blackthorn has a traditional association with the cycles of life and death. Because of this, it is often used in the Celtic celebration of Imbolc, welcoming the beginning of spring.