Lignin

**Definition:** The most abundant natural aromatic organic polymer found in all vascular plants. Lignin together with cellulose and hemicellulose are the major cell wall components of the fibers of all wood and grass species. Lignin is composed of coniferyl, p-coumaryl, and sinapyl alcohols in varying ratios in different plant species. (From Merck Index, 11th ed)

**Tree numbers:** - D05.750.078.562.180.515 - D05.750.078.687 - D20.538 - D25.720.099.687 - J01.637.051.720.099.687