The Celtic Rowan Pillow.  The ancient Celts prized the oak over other trees and today the oak wood is still prized for its hard wood and natural beauty. Each few (letter) of the ancient Irish writing called Ogam (pronounced owam) is associated with a sacred tree. The Ogam few called “duir” represents the oak and is incorporated on this pillow pattern. This design is one in a series of Celtic botanical knits created to draw attention to the beauty of our planet.