Glossary of Plant Systematics (1st ed.) by Simpson (2006)
- An individual member or segment of the corolla, typically (nongreen) colored and functioning as an attractant for pollination. (flower part, perianth part)
Glossary of "Life (9th ed.)" by Sadava et al. (2011)
- In an angiosperm flower, a sterile modified leaf, nonphotosynthetic, frequently brightly colored, and often serving to attract pollinating insects.
- Simpson, M. G. 2006. Plant Systematics. -xi + 590 pp. Elsevier Academic Press, Oxford.
- 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.