broom: [OE] Broom was originally the name of the yellow-flowered bush; its application to the long-handled brush did not come about until the 15th century (the underlying notion is of a brush made from broom twigs tied to a handle). The plant-name occurs throughout the Germanic languages, but it is applied to quite a wide range of plants: Old High German brāmma, for instance, is a ‘wild rose’; Old Saxon hiopbrāmio is a ‘hawthorn bush’; and English bramble probably comes from the same source. => bramble
broom (n.)
Old English brom "broom, brushwood," the common flowering shrub whose twigs were tied together to make a tool for sweeping, from Proto-Germanic *bræmaz "thorny bush" (cognates: Dutch braam, German Brombeere "blackberry"), from PIE root *bh(e)rem- "to project, a point."
Traditionally, both the flowers and sweeping with broom twigs were considered unlucky in May (Suffolk, Sussex, Wiltshire, etc.). The witch's flying broomstick originally was one among many such objects (pitchfork, trough, bowl), but the broomstick became fixed as the popular tool of supernatural flight via engravings from a famous Lancashire witch trial of 1612.