Red Brome
Bromus rubens
Description: Red brome (Bromus rubens) is a tufted bunchgrass, usually growing from 8 to 20 inches tall. Several to numerous stems spread upwards from the base of the plant. Its color is light green during the growing season, changing to a light straw yellow when mature. The leaves are about two to four inches long and sparely covered with fine, fuzzy hairs. Clusters of seedheads from one and a half to three inches long grow on the ends of unbranched stems of mature plants. The seedheads are reddish-brown to purplish in color.1
Habitat: In the United States, red brome normally occurs on open hillsides and woodland or chaparral areas. It is particularly common where native perennial grass cover as deteriorated.1
Total Range: B. rubens is native to the Mediterranean and the Near East. It was introduced into the southwestern United States in the early 1900's, and is now spreading throughout both the Sonoran and Mojave Deserts due to favorable climatic conditions in these areas.3
Threat to Native Species and/or Environments: Red brome has a short growing period and low palatability, making it mostly useless as a forage grass. Its high seed content and dense growth allow it to quickly spread and take over natural environments which have been disturbed by human activities. Once established, red brome changes an area's fire regimes by increasing fuel loads, thus increasing the spread and intensity of fires.2 The increased fire activity can severely burn, and possibly kill, native species which are not accustomed to such occurrences. Its use of winter moisture and soil nutrients affects the diversity and/or abundance of native spring annuals.2
Red brome in Pima County: Red brome was reported in Tucson by 1909. It was probably first introduced to the area when it was presented as a potential forage plant in the Santa Rita Experimental Range.3 It continues to spread into many other areas in the Sonoran Desert uplands of Pima County.
References
1 "Arizona Range Grasses, " 1997, Cooperative Extension, College of Agriculture, The University of Arizona, Tucson, Arizona, 85721. Publication AZ97105.
2 James, D. Spring/Summer 1995. The threat of exotic grasses to the biodiversity of semiarid ecosystems. The Arid Lands Newsletter. Issue No. 37, ISSN 1092-5481
3 Felger 1990. Non-native plants of Organ Pipe Cactus National Monument, Arizona. Technical Report No. 31, Cooperative National Park Resources Studies Unit. School of Renewable Natural Resources, the University of Arizona. 93 pp.