Culms 2-16 cm. Panicles 1-3 cm, often reduced to 1 spikelet. Lemmas 6.5-7.5 mm, pubescent or glabrous, margins bluntly angled; awns sometimes divaricate at maturity. Caryopses shorter than the paleas.

Bromus hordeaceus subsp. thominei grows along the Pacific coast of Canada, from the Queen Charlotte Islands to Vancouver Island, as well as at inland locations in British Columbia; it has also been recorded from California, Massachusetts, and Rhode Island.