Lignin changed the planet — this 400-million-year-old molecule made trees possible, and without it Earth would still be covered in low moss instead of forests.
A complex organic polymer that forms the structural material in the cell walls of plants, making wood rigid and woody plants possible.
Coined from Latin lignum (wood, timber, firewood) + the chemical suffix -in. Latin lignum derives from legere (to gather, to collect), because wood was gathered as fuel. The word was introduced to chemistry in 1819 by the Swiss botanist Augustin Pyramus de Candolle. Key roots: *leǵ- (Proto-Indo-European: "to gather, to collect"), lignum (Latin: "wood, timber (that which is gathered)").