It is theorized that wheat's ancestors (Triticum monococcum, Aegilops speltoides, and Aegilops tauschii, all diploid grasses) hybridized naturally over millennia somewhere in West Asia, to create natural polyploid hybrids, the best known of which are common wheat and durum wheat.
The loganberry (Rubus × loganobaccus) is an hexaploid hybrid produced from pollination of a plant of the octaploid blackberry cultivar 'Aughinbaugh' (Rubus ursinus) by a diploid red raspberry (Rubus idaeus).
In Crepis and some other herbaceous perennial species, a polyploid complex may arise where there are at least 2 genetically isolated diploid populations, in addition to auto- and allopolyploid derivatives that coexist and interbreed (hybridise).
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The polyploid complex was first described by E. B. Babcock and G. Ledyard Stebbins in their 1938 monograph The American Species of Crepis: their interrelationships and distribution as affected by polyploidy and apomixis.