Oak bark (Quercus robur)
The oak (Quercus robur) is a plant species from the beech family (Fagaceae) and grows to a height of 20 to 40 m and a trunk circumference of up to three metres, in the open up to 8 metres. Oaks can reach an age of 500 - 1000 years. The oak is an ancient cult tree and was dedicated to the Germanic god Donar or Thor. The Celts called it Dair from which the word Druid was derived.
Oak bark was already used by the Germanic and Celtic peoples as an additive to incense against negative influences and entities.