Monocotyledonous angiosperms do not have secondary growth and hence do not make wood. As mentioned above, these are produced by differential growth through the growing season. They are usually associated with rapid growth in spring or the wet season and slower growth later in the year. Characteristics of woods Woods differ in color, porosity, grain and figure. See the illustrations on page 550.
Porosity is mainly a function of dicot woods.
This term refers to how the vessels are distributed. Grain refers to the alignment of the xylem cells. The presence of knots or burls may also be involved. The figure also differs greatly depending on how the wood is cut. Density is the weight per unit size.