Glossary of "Plant Biology (1st ed.)" by Graham et al. (2003)
- Modified leaves, some of which are colorful and serve in attraction of pollinators to flowers.
Glossary of Plant Systematics (1st ed.) by Simpson (2006)
- A modified, generally reduced leaf, generally found associated with reproductive organs, e.g. subtending the ovuliferous scale of conifers of the flowers or inflorescence axes of flowering plants. Adj: bracteate. (leaf structural type)
- 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.