Publication: Botanische Abhandlungen und Beobachtungen.
selected vouchers: WTU
Notes: FNA24: "Bromus diandrus is native to southern and western Europe. It is now established in North America, where it grows in disturbed ground, waste places, fields, sand dunes, and limestone areas. It occurs from southwestern British Columbia to Baja California, Mexico, and eastward to Montana, Colorado, Texas, and scattered locations in the eastern United States. The common name "˜ripgut grass' indicates the effect it has on animals if they consume the sharp, long-awned florets of this species.
Bromus diandrus, as treated here, includes B. rigidus Roth. Sales (1993) reduced these two taxa to varietal rank, pointing out that the differences between them in panicle morphology and callus and scar shape are subtle enough that identification of many specimens beyond B. diandrus sensu lato is often impossible."