Bromus densus Swallen Bromus densus Swallen in Contr. U.S. Natl. Herb. 29(9): 396. 1950 sec. Dávila & al. 2018=Bromopsis densa (Swallen) Holub in Folia Geobot. Phytotax. 8(2): 167. 1973 syn. sec. Dávila & al. 2006