The genomic relationships of the Australian species in the Gossypium genus are poorly understood. Hybrids were made among some of the species to determine chromosome affinities. These included G. australe crossed with G. nelsonii, G. bickii and G. pulchellum, and G. pulchellum crossed with G. sturtianum and G. costulatum. Based on fertility of hybrids and chromosome affinities G. australe, G. nelsonii and C. bickii are in the same genome group. It is proposed that their respective genome designations tentatively be *C(3-a), *C(3-n), and *C⁴ since limited published data indicate that G. australe and G. sturtianum have close chromosome homeology (13 bivalents). More complete data from hybrids involving C(1) are necessary to remove the tentative (*) label. The Kimberley cottons, as exemplified by G. pulchellum, have the largest chromosomes of the genus, have reduced chromosome homeology to the C genome with at least one end rearrangement, and form sterile hybrids with G. sturtianum and G. australe. It is proposed that a new genome group, designated K, be recognized to accommodate the Kimberley cottons. Since the taxonomic and cytogenetic treatment of the group is incomplete, species subscripts should not be assigned at this time.