Genus of ryegrass is "Lolium."

...The classification of Lolium grasses (click here) has long been a source of contention. On the basis of its spike-like inflorescence structure, early researchers placed the genus Lolium in the grass tribe Triticeae (reviewed in Darbyshire, 1993). However, accumulating evidence based on hybridization and cytology (Jenkin, 1959), endosperm structure (Tateoka, 1962), serology (Butkute and Konarev, 1980), chloroplast DNA restriction sites (Soreng et al., 1990), thermal denaturation of genomic DNA (King and Ingrouille, 1987), and sequence-based phylogenies (Catalán et al., 1997; Mathews et al., 2000; Soreng and Davis, 1998) have supported placement of the genus Lolium together with Festuca in the tribe Poeae. In the course of grass evolution, spike and panicle forms of grass inflorescences have frequently arisen from each other, so gross inflorescence morphology is particularly unreliable for identifying major evolutionary relationships. Although the difference between a fescue panicle and the ryegrass spike seems dramatic to the specialist's eye, a more scientific classification system should emphasize more evolutionarily relevant characters and genetic relationships.