E-Flora BC: Electronic Atlas of the Flora of British Columbia

Bromus tectorum L.
cheatgrass (downy brome)
Poaceae (Grass family)

Introduction to Vascular Plants

© Ryan Durand  Email the photographer   (Photo ID #13593)

E-Flora BC Static Map
Distribution of Bromus tectorum
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Introduction

This is an introduced, self-pollinating (sometimes cross-pollinating) (Thill et al. 1984) winter annual species native to Europe and southwestern Asia: it is now present throughout Europe, western and central Asia, Japan, South Africa, Canada and the United States, and Australia and New Zealand [there are recent reports from South America and India] (Global Invasive Species Database 2005). It was brought to North America circa 1860 as livestock forage (Global Invasive Species Database 2005), with the first collection made from Pennsylvania in 1861 (Stewart and Hull 1949). By 1928 it invaded much of the perennial grasslands of Washington, Idaho, Oregon, Utah, Nevada and British Columbia. It presently carpets areas of occurrence as a dominant species (Humphrey and Schupp 2001), including throughout the Okanagan. It is a fire-prone, ecosystem altering species, and can out-compete native species particularly following fire (Global Invasive Species Database 2005). Increased fire risk is associated with increased cover of cheatgrass (Link et al. 2006). Recruitment occurs in late summer and autumn, but may continue into the next year (Mack and Pyke 1983). This is a seed banking species; seed banks are reduced by fire, but recover quickly (Humphrey and Schupp 2001). Cheatgrass is bright green when young, turning a straw colour when old and dried--its most flammable period (Globa Invasive Species Database 2005). The earliest BC collection for this species in the UBC Herbarium was made by Eli Wilson in 1912, from Summerland in the Okanagan. It was collected from Spence's Bridge by John Davidson in 1913.

Species Information

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General:
Annual grass from fibrous roots; stems more or less densely hairy, the hairs fine, soft, short to moderately long and straight, (10) 20-50 (70) cm tall.
Leaves:
Sheaths soft-hairy; blades 2-3 (4) mm wide, flat, hairy, the hairs fine, soft, short to moderately long, straight; ear-shaped lobes lacking at the leaf-bases; ligules jagged, 1.2-3 mm long.
Flowers:
Inflorescence a somewhat compact panicle, erect at first then mostly drooping to one side, (3) 6-15 cm long, the branches slender, the lower and longer ones often drooping, bearing usually (3) 4 or more spikelets; spikelets 3- to 6-flowered, slender, broadest above the midlength, smooth, up to 2 cm long; florets mostly small, closed, self-fertilizing; glumes smooth to long-hairy, the lower ones 1-nerved, 4-6 (9) mm long, the upper ones 3-nerved, 7-13 mm long; lemmas smooth to long-hairy, slightly keeled, 9-12 mm long, narrowly sharp- to long-pointed, often purplish when mature, awned, the awns straight to slightly bent, 10-17 mm long, bidentate, the teeth long pointed, 2-3 mm long; anthers 0.5-0.7 mm long, usually included.

Source: The Illustrated Flora of British Columbia

Habitat / Range

Dry to mesic roadsides, disturbed sites, waste places, meadows, grasslands and shrublands in the lowland, steppe and montane zones; common in S BC, rare elsewhere; introduced from Eurasia and N Africa.

Source: The Illustrated Flora of British Columbia

Ecology

Ecological Framework for Bromus tectorum

The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)

Site Information
Value / Class

Minimum

Average

Maximum

Elevation (metres) 61 681 1827
Slope Gradient (%) 0 28 210
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
0 192 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
0 2 7
Modal Nutrient Regime
Class
C
Number of field plots
 species was recorded in:
1077
Modal BEC Zone Class
BG
All BEC Zones (# of stations/zone) species was recorded in: BG(338), CDF(7), ESSF(4), ICH(33), IDF(329), MS(11), PP(301)

Climate

The climate type for this species, as reported in the: "British Columbia plant species codes and selected attributes. Version 6 Database" (Meidinger et al. 2008), is not evaluated, unknown or variable.

Synonyms and Alternate Names

Anisantha tectorum (L.) Nevski
Bromus tectorum var. glabratus Spenner
Bromus tectorum var. hirsutus Regel
Bromus tectorum var. nudus Klett & Richt.

Taxonomic and Nomenclatural Links

Additional Photo Sources

Related Databases

Species References

Global Invasive Species Database. 2005. Bromus tectorum page. Invasive Species Specialist Group, International Union for the Conservation of Nature.

Humphrey, L. David and Eugene W. Schupp. 2001. Seed banks of Bromus tectorum-dominated communities in the great basin. Western North American Naturalist 61 (1): 85-92.

Link, S.O., Keeler, C.W., Hill, R.W. and Hagen, E. Bromus tectorum cover mapping and fire risk. International Journal of Wildland Fire 15 (1): 113-119.

Mack, Richard N. and David A. Pyke. 1983. The demography of Bromus tectorum: variation in time and space. Journal of Ecology 71: 69-93.

Stewart, George and A. C. Hull. Cheatgrass (Bromus tectorum L.)--An Ecologic Intruder in Southern Idaho. Ecological Society of America.

Thill, Donald C., K. George Beck, and Robert H. Callihan. 1984. The Biology of Downy Brome (Bromus tectorum). Weed Science 32: Supplement 1: 7-12.

General References