Glossary of "Life (9th ed.)" by Sadava et al. (2011)
- A complex, hydrophobic polyphenolic polymer in plant cell walls that crosslinks other wall polymers, strengthening the walls, especially in wood.
Glossary of Plant Systematics (1st ed.) by Simpson (2006)
- A complex polymer of phenolic compounds that impregnates the secondary cell wall of some cells (including tracheary elements and sclerenchyma), functioning to impart strength and rigidity to the wall.
Glossary of "The Evolution of Plants (2nd ed.)" by Willis & McElwain (2014)
- Biomolecules made up of complex carbohydrate polymers and found in plant cells and tissues with a support function, e.g. in water-conducting cells such as xylem.
- Sadava, D., Hillis, D. M., Heller, H. C. & Berenbaum, M. R. 2011. Life: The Science of Biology, 9th ed. -xliv + 1266 pp. Sinauer Associates, Inc., Sunderland.
- Simpson, M. G. 2006. Plant Systematics. -xi + 590 pp. Elsevier Academic Press, Oxford.
- Willis, K. J. & McElwain, J. C. 2014. The Evolution of Plants, 2nd ed. -ix + 398 pp. Oxford University Press, Oxford.