Glossary of "Plant Biology (1st ed.)" by Graham et al. (2003)
- The triploid nutritive tissue formed as one result of double fertilization.
Glossary of Plant Systematics (1st ed.) by Simpson (2006)
- The triploid tissue that develops from mitotic divisions of the endosperm cell (the product of double fertilization), ultimately enveloping or abutting the embryo and functioning as the nutritive tissue of angiosperm seeds.
Glossary of "Evolution of Plants (2nd ed.)" by Willis & McElwain (2014)
- Graham, L. E., Graham, J. M. & Wilcox, L. W. 2003. Plant Biology. -xxxv + 497 pp. Pearson Education, Inc., Upper Saddle River.
- 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.