Glossary of Plant Systematics (1st ed.) by Simpson (2006)
- A cell of the sporangium that undergoes meiosis, producing (generally four) haploid spores.
Glossary of "Life (9th ed.)" by Sadava et al. (2011)
- Specialized cells of the diploid sporophyte that will divide by meiosis to produce four haploid spores. Germination of these spores produces the haploid gametophyte.
- 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.