Abnormal wood formed on the lower side of branches and inclined trunks of softwood (conifers) trees. Compression wood is identified by its relatively wide annual rings, usually eccentric, relatively large amount of summerwood, sometimes more than 50 percent of the width of the annual rings in which it occurs, and its lack of demarcation between springwood and summerwood in the same annual rings. Compression wood compared with normal wood, shrinks excessively lengthwise.