Purple living bone ("Purpurowy żywokost" in the original Polish) is a symbiotic root used by the dryads of Brokilon in conjunction with Conynhaela, a magical herb. Together, they enable the rapid regeneration of damaged or broken bones. After the Thanedd coup, Geralt spent 36 days in Brokilon being treated for a broken leg and forearm and extensive use of both conynhaela and purple living bone was made.