June 5, 1806, at Camp Chopunnish, Idaho County, Idaho.

Mountain brome is a member of the grass family (family Poaceae). Grasses are herbs, rarely woody, with cylindrical, jointed flowering stems (culms), hollow between the joints, leaves often mostly basal and tiny flowers aggregated into highly modified clusters.

Grasses occur throughout the world in almost every habitat.

The greatest diversity of grasses are found in the tropical zone, and the greatest abundance in the temperate regions.