Tree heather (Erica arborea) forms a thick shrub, but in the Mediterranean reaches tree size in suitable conditions. The knots formed at the junction between stem and roots are used in briar tobacco pipes because the acid content of the wood makes it almost impossible to burn.


Trees and shrubs of the Mediterranean by Helge Vedel, translated from the Danish by Aubrey Rush (Penguin Guides, 1978), p.49