Glastonbury Holy Thorn

The Glastonbury Thorn (Crataegus monogyna 'Biflora') is a cultivar of common hawthorn that flowers twice a year—once in early spring and once in winter, typically around Christmas—which distinguishes it from every native British hawthorn. This unusual flowering habit is the botanical foundation on which a remarkable body of Christian legend has been built, linking Glastonbury to the earliest arrival of Christianity in the British Isles.

The legend of Joseph of Arimathea planting his staff on Wearyall Hill (from 'we are weary all'—a folk etymology for the hill's name) and having it take miraculous root does not appear in its full form until the 17th century; the most famous version of the story is first recorded in 1662. Earlier medieval sources, including the 12th-century writings of William of Malmesbury and Gerald of Wales, connect Joseph to Glastonbury as the founder of Britain's first Christian community, but they do not mention the thorn or the staffplanting. The biflora flowering appears to have attracted the Joseph legend to it rather than the legend generating the tree. The hawthorn's winter flowering was consistently interpreted as a miraculous sign: even after the Reformation, and despite Puritan hostility, locals preserved cuttings from successive trees.

The tradition of sending a flowering sprig to the sovereign at Christmas—which is maintained to this day by the vicar of St John the Baptist, Glastonbury—was formalised no later than the early 17th century and has continued through multiple monarchs. The 'original' tree on Wearyall Hill was destroyed during the English Civil War; a replacement planted on the hill in 1951 was vandalised in 2010, with all its branches cut off. The tree in the churchyard of St John's and a specimen at Glastonbury Abbey remain the principal living representatives of the tradition. The University of Reading's Glastonbury Abbey Archaeology Project has published scholarly analysis of the thorn's place in the Joseph legend.