Glossary of Plant Systematics (1st ed.) by Simpson (2006)
- Margins curved, widest near base, length:width ratio between 6:1 and 3:1. (shape)
Glossary of "The Evolution of Plants (2nd ed.)" by Willis & McElwain (2014)
- Narrowing or tapering of the leaf at both ends resulting in a 'spear-shaped' leaf.
- Willis, K. J. & McElwain, J. C. 2014. The Evolution of Plants, 2nd ed. -ix + 398 pp. Oxford University Press, Oxford.