The light colored phase of the annual ring, formed by the large cells used for root sap movement in the spring.
The less dense, larger wood cells of an annual growth ring. Also called earlywood to refer to the fact that it is the wood formed early in the growing season. See also summerwood.
The portion of the annual growth ring of a tree that is formed during the early part of the seasons growth. It is usually less dense and weaker mechanically than the summerwood.