Class of complex organic polymers supporting tissues of vascular plants. Such complex aromatic heteropolymers, stiffen and fortify secondary cell walls within xylem tissues, creating a dense matrix that binds cellulose microfibrils and crosslinks other wall components, thereby preventing the collapse of conductive vessels, lending biomechanical support to stems, and allowing plants to adopt an erect-growth habit.

Martone, PT, Estevez, JM, Lu, F; Ruel, K, Denny, MW, Somerville, C; Ralph, J (2009). Discovery of Lignin in Seaweed Reveals Convergent Evolution of Cell-Wall Architecture. Current biology : CB 19 (2): 169–75.doi:10.1016/j.cub.2008.12.031

Source category: Scientific & Technical Literature

Complex oxygen-containing organic substance that, with cellulose, forms the chief constituent of wood. It is second only to cellulose as the most abundant organic material on Earth. [...] It is a mixture of complex, apparently polymeric compounds of poorly known structure. Lignin is concentrated in the cell walls of wood and makes up 24–35 percent of the oven-dry weight of softwoods and 17–25 percent of hardwoods.

Encyclopædia Britannica, 2015, accessed 18 December 2023

Source category: Dictionaries