Brachyelytrum is a small grass genus that occurs in eastern North America and eastern Asia. It is one of several grass species that displays this classic floristic disjunction pattern. There are three species recognized currently in Brachyelytrum: B. aristosum (distributed in southeastern Canada and the northeastern USA), B. erectum (distributed in the northeastern USA and adjacent southern Canada), and B. japonicum (distributed in Japan and southeastern China).
Recent molecular phylogenetic study has indicated that, within the grass family (Poaceae) Brachyleytrum is the sister-group of the subfamily Pooideae (the cool season grasses), a lineage that includes many of the world's major cereal crops such as barley, wheat, and oats.