Glossary of "Plant Systematics (1st ed.)" by Simpson (2006)
- A group of individuals of the same species that is usually geographically delimited and that typically have a signifcant amount of gene exchange.
Glossary of "Ecology (6th ed.)" by Krebs (2009)
- a group of organisms of the same species occupying a particular space at a particular time.
Glossary of "Life (9th ed.)" by Sadava et al. (2011)
- Any group of organisms coexisting at the same time and in the same place and capable of interbreeding with one another.
Glossary of "Evolution (4th ed.)" by Futuyma & Kirkpatrick (2017)
- A group of conspecific organisms that occupy a more or less well defined geographic region and exhibit reproductive continuity from generation to generation; ecological and reproductive interactions are more frequent among these individuals than with members of other populations of the same species.
Glossary of "Environmental Science: Earth as a Living Planet (2nd ed.)" by Botkin & Keller (1998)
- A group of individuals of the same species living in the same area or interbreeding and sharing genetic information.
- Botkin, D. B. & Keller, E. A. 1998. Environmental Science: Earth as a Living Planet, 2nd ed. -xxxxii + 649 pp. John Wiley & Sons, Inc., New York.
- Krebs, C. J. 2009. Ecology, 6th ed. -xvi + 655 pp. Pearson Benjamin Cummings, San Francisco.
- Futuyma, D. J. & Kirkpatrick, M. 2017. Evolution, 4th ed. -xviii + 602 pp. Sinauer Associates, Inc., Sunderland.
- 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.
- Simpson, M. G. 2006. Plant Systematics. -xi + 590 pp. Elsevier Academic Press, Oxford.