Plant Species: Bromus marginatus, mountain bromegrass
Kingdom: Plantae
Phylum: Magnoliophyta -- flowering plants
Class: Liliopsida -- monocots
Family: Poaceae -- grass
Genus: Bromus
Species: marginatus
Variety:
Common Name: mountain brome
Species Code: BRMA4
Origin: Native to grasslands and open forests of western North America.
Rare: no
Form: grass, short-lived perennial, caespitose, 30-100 cm tall, glabrous or pubescent.
Duration: perennial
Longevity: short
Habitat Type: prairie, forest
Wetland Indicator Status: not listed
Leaves: sheaths closed to near the top; auricles tiny; ligules 1-3 mm, erose; blade flat or slightly involute, 3-12 mm wide.
Mature height: 12-40 inches
Flowers: borne in a panicle with the branches often erect or ascending, spikelets strongly compressed, glumes and lemmas keeled, awn 4-7 mm long, straight.
Flowers color: inconspicuous
Bloom: June
Bloom starts on:
Bloom ends on:
Fruit: caryopsis, disarticulation above the glumes.
Vegetation type:
Characteristics:
>B. marginatus and B. carinatus are treated by some as separate taxa and by others as part of a continuum within a single highly variable species.
Reproduces sexually by seed.
60,475-145,000 seeds/lb (Hassell et al 1996).
106,680 seeds/lb (USDA NRCS PLANTS Database 2006).
2n=56. 42 and 70 have also been reported in B. marginatus (Hitchcock et al 1969). The Manual of Grasses for North America treats them as varieties of B. carinatus with var. carinatus 2n= 28, 56 and var. marginatus 2n=42 (Paulick & Anderton 2009).
Primarily wind pollinated.
Flowers are perfect.
Fruit is a caryopsis.
Usually self-pollinated, frequently cleistogamous (Baldwin et al 2004).
Depending on conditions, may produce at least some seed by cleistogamy (Harlan 1945).
Livestock, elk, and deer eat the plants, birds and rodents eat the seeds of B. carinatus (Stubbendieck et al 1997). A highly valuable forage for Rocky Mountain elk in winter (Kufeld 1973).
Bromus and Calamagrostis species are hosts for the larva of the arctic skipper butterfly, Carterocephalus palaemon. Many grasses are hosts for the larva of the common wood nymph (Cercyonis pegala) and the common ringlet (Coenonympha californica) butterflies (Pocewicz 2005).
Comments: Plants respond to nitrogen fertilizer with increased biomass and seed production (Stark et al 1947).
Native Bromus species are susceptible to head smut (Ustilago bullata). Resistance to head smut varies by genotype (Kreizinger et al 1948).
Sun requirement: full
Soil moisture: mesic
Precipitation: 10-20 inches (USDA NRCS PLANTS Database 2009).
Fire: Dormant plants of B. carinatus may survive low to medium intensity fires and recolonize readily by seed (Tollefson 2006). B. marginatus should respond in a very similar manner.
Hazards:
Sowing time: spring
Transplant time: spring
Stratification: none required
Seed yield: high
Seed harvest: easy
Seed first harvest: 2nd year
Seed cleaning: easy
Planting duration: 4 years
Seed insect problem: none noted
Seed shatter: medium
Seed size: large
Seed harvest date: early July
Seed comments: seed shatters more readily with increased maturity
Key words:
Alternate Genus:
Alternate Species: carinatus
Alternate Variety: marginatus
Propagation:
B. marginatus and
B. carinatus are sometimes treated as separate species or varieties and sometimes as part of a continuum within a single highly variable species.
There are 6 protocols in the
Native Plant Network database under both names.
Whether or not they are considered separate species, seed germinates readily without pretreatment.
Germinates at a wide range of temperatures (Plummer 1943).
Reproduces sexually by seed.
Notes:
References:
Ashby, William C., and Henry Hellmers. 1955. Temperature Requirements for Germination in Relation to Wild-land Seeding. Journal of Range Management 8:80-83.
Baldwin, B.G., S. Boyd, B.J. Ertter, D.J. Keil, R.W. Patterson, T.J. Rosatti, and D.H. Wilken (eds). 2004. Jepson Online Interchange for California Floristics. University and Jepson Herbaria, University of California, Berkeley, CA. Accessed 7/25/09 online at http://ucjeps.berkeley.edu/interchange.html
Carter, J.F., and A.G. Law. 1948. The Effect of Clipping upon the Vegetative Development of Some Perennial Grasses. Journal of the American Society of Agronomy 40:1084-1091.
Dremann, Craig. 2003. Observations on Bromus carinatus and Elymus glaucus Seed Storage and Longevity. Native Plants Journal 4(1):61-64.
Harlan, Jack R. 1945. Cleistogamy and Chasmogamy in Bromus carinatus Hook. & Arn. American Journal of Botany 32:66-72.
Hassell, Wendell, W. Rocky Beavers, Steve Ouellette, and Thomas Mitchell. 1996. Seeding Rate Statistics for Native and Introduced Species. US Dept of Interior and USDA, NRCS. Denver, CO.
Hitchcock, C. Leo, Arthur Cronquist, Marion Ownbey, and J.W. Thompson. 1969. Vascular Plants of the Pacific Northwest. University of Washington Press. Seattle, WA. 5 vol.
Kreizinger, E.J., George W. Fischer, and A.G. Law. 1947. Reaction of Mountain brome and Canada wildrye Strains to Heat Smut (Ustilago bullata). Journal of Agricultural Research 75:105-111.
Kufeld, Roland. 1973. Foods Eaten by the Rocky Mountain Elk. Journal of Range Management 26:106-113.
Massa, Alicia N., and Steven R. Larson. 2005. Phylogeography of North American Mountain Bromes. Native Plants Journal 6(1):29-35.
Pavlick, L.E., and L.K. Anderton. Bromus. In: Manual of Grasses for North America. Intermountain Herbarium, Utah State University, Logan Utah. Online at http://www.herbarium.usu.edu/webmanual/ Accessed 7/26/09.
Plummer, A. Perry. 1943. The Germination and Early Seedling Development of Twelve Range Grasses. Journal of the American Society of Agronomy 35:19-34.
Pocewicz, Amy. 2005. Host Plants of Palouse Butterfly Species. 2 page handout to accompany the April 2005 presentation to the Palouse Prairie Foundation.
Stark, R.H., A.L. Hafenrichter, and K.H. Klages. 1949. The Production of Seed and Forage by Mountain Brome as Influenced by Nitrogen and Age of Stand. Agronomy Journal 41:508-512.
Stubbendieck, James, Stephan L. Hatch, and Charles H. Butterfield. 1997. North American Range Plants. 5th edition. University of Nebraska Press, Lincoln, NE. 501 pp.
Tollefson, Jennifer E. 2006. Bromus carinatus. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/ [2008, February 11].
USDA, NRCS. 2009. The PLANTS Database (http://plants.usda.gov, 26 July 2009). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.