Bonnie's on to something, I think. I found this ...

"LAUREL--Both in Medieval and Roman times, the Laurel tree was believed to protect one from lightening. It was believed by the Romans that if a person stood under a Laurel tree they would be protected from the plague. In Medieval times they also believed that standing under the Laurel tree would protect from witches. Daphne , according to the ancient myths, was changed into to Laurel tree by her father to keep Apollo's love advances at bay. Apollo who was smitten with her by Cupid's arrow, was in awe of the tree ,made it sacred and announced he would wear the leaves around his head.. The Laurel wreath was worn around the heads of triumphant men such as the soldiers, statesmen, and poets."

sian