- Commercial cotton species
- Gossypium arboreum L. – tree cotton, native to India and Pakistan
- Gossypium barbadense L. – known as American, Creole, Egyptian, or sea island cotton, native to tropical South America
- Gossypium herbaceum L. – Levant cotton, native to southern Africa and the Arabian Peninsula
- Gossypium hirsutum L. – upland cotton, native to Central America, Mexico, the Caribbean and southern Florida, the most commonly grown species in the world
- Noncommercial species
- Gossypium australe F.Muell – endemic to northwestern Australia
- Gossypium darwinii – Darwin's cotton, found only on the Galapagos Islands
- Gossypium sturtianum J.H. Willis – Sturt's Desert Rose, native to Australia
- Gossypium thurberii Tod. – Arizona wild cotton, native to Arizona and northern Mexico
- Gossypium tomentosum Nutt. ex Seem – Ma‘o or Hawaiian cotton, endemic to the Hawaiian Islands
- Gossypium raimondii – one of the putative progenitor species of tetraploid cotton, alongside G. arboreum
Many varieties of cotton have been developed by selective breeding and hybridisation of the above species. Experiments are ongoing to cross-breed various desirable traits of wild cotton species into the principal commercial species, such as resistance to insects and disease, and drought-tolerance.
Most wild cottons are diploid, but there is a group of five species from America and Pacific islands which are tetraploid, apparently due a single hybridisation 0.5 to 2 million years ago. The tetraploid species are G. hirsutum, G. tomentosum, G. mustelinum, G. barbadense, and G. darwinii.
- "Gossypieae L.". Germplasm Resources Information Network. United States Department of Agriculture. 2007-03-12. Retrieved 2009-02-20.
- Small, R. L. (1 September 1998). "The Tortoise and the Hare: Choosing between Noncoding Plastome and Nuclear Adh Sequences for Phylogeny Reconstruction in a Recently Diverged Plant Group". American Journal of Botany 85 (9): 1301. DOI:10.2307/2446640. ISSN 00029122.