Many wood chemists and biochemists feel that there is some covalent interaction between lignin and polysaccharide, but not direct evidence has yet been presented. The extractives would then be coating this structure providing resistance to pathogens. Characteristics of Various Types of Woods in Hardwoods and Softwoods A. Compression Wood 1. Found in Ginkgo and all conifers. Typically on the lower side.
Wide growth rings on the lower side.
Lignin contains more p-coumaryl residues than normal wood. Present in all forest and plantation trees. Compression wood, by expanding along the grain when it is formed, makes it possible for conifer trees to perform movements of orientation. A displaced stem bends up again, a bent down branch moves back up. If the leader is destroyed, a branch below bends upward, replacing the leader nd developing a new stem.