Glossary of "Plant Biology (1st ed.)" by Graham et al. (2003)
- A plant that requires two growing seasons to complete its life cycle. Biennial plants store food reserves from the first growing season and flower and set seed in the second season.
- Graham, L. E., Graham, J. M. & Wilcox, L. W. 2003. Plant Biology. -xxxv + 497 pp. Pearson Education, Inc., Upper Saddle River.