Comments on Genomic Genera in the Triticeae (Poaceae)

Generic delimitation in the Triticeae has long been problematical because the extensive hybridization in the group is not readily accomodated in a hierarchical classification. The genomic genera of Löve (1984) are one solution, but fully one‐third of them are polyphyletic, incorporating 2 or more genomes. The suggestion that the tribe be considered a single genus (Stebbins, 1956) is theoretically defensible—the genus would be strictly monophyletic—but probably impractical. This paper presents a cladistic analysis of the tribe that differs from previous analyses in that it uses only strictly monophyletic (monogenomic) groups as terminal taxa; hybrids (heterogenomic groups) are shown as reticulations. Monophyletic groups can then be delimited to minimize the number of polyphyletic genera. A classification incorporating genomic information is derived from the phylogeny.