''Bromus madritensis'' is a species of

brome grass ''Bromus'' is a large genus of grasses, classified in its own tribe Bromeae. They are commonly known as bromes, brome grasses, cheat grasses, or chess grasses. Estimates in the scientific literature of the number of species have ranged from 100 ...

known by the common name compact brome. The

specific epithet In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

''madritensis'' refers to

Madrid Madrid ( ; ) is the capital and List of largest cities in Spain, most populous municipality of Spain. It has almost 3.5 million inhabitants and a Madrid metropolitan area, metropolitan area population of approximately 7 million. It i ...

Spain Spain, or the Kingdom of Spain, is a country in Southern Europe, Southern and Western Europe with territories in North Africa. Featuring the Punta de Tarifa, southernmost point of continental Europe, it is the largest country in Southern Eur ...

. It has a diploid number of 28. There are two subspecies: *''Bromus madritensis'' subsp. ''madritensis'': panicles less dense, stem and leaf sheath less hairy *''Bromus madritensis'' subsp. ''rubens'' ( syn. ''Bromus rubens'') – foxtail brome, foxtail chess, red brome: dense panicles and slightly hairy stems

Description

''Bromus madritensis'' is an winter annual grass, growing solitary or tufted, with erect or ascending culms growing high. The leaf sheaths are downy or slightly hairy. The grass lacks auricles and the glabrous

ligule A ligule (from "strap", variant of ''lingula'', from ''lingua'' "tongue") is a thin outgrowth at the junction of leaf A leaf (: leaves) is a principal appendage of the plant stem, stem of a vascular plant, usually borne laterally above g ...

s are long. Its flat leaf blades are either glabrous or slightly hairy, and measure long and wide. The erect and ellipsoid

panicle In botany, a panicle is a much-branched inflorescence. (softcover ). Some authors distinguish it from a compound spike inflorescence, by requiring that the flowers (and fruit) be pedicellate (having a single stem per flower). The branches of a p ...

s are long and wide, with short branches that ascend and slightly spread. The branches never droop and bear one or two

spikelet A spikelet, in botany, describes the typical arrangement of the inflorescences of grasses, sedges and some other monocots. Each spikelet has one or more florets. The spikelets are further grouped into panicles or spikes. The part of the sp ...

s each. The spikelets are long, longer than the panicle branches, and bear seven to eleven

floret This glossary of botanical terms is a list of definitions of terms and concepts relevant to botany and plants in general. Terms of plant morphology are included here as well as at the more specific Glossary of plant morphology and Glossary ...

s. The spikelets vary in color from green to distinctly purplish-red. The lightly hairy

glume In botany, a glume is a bract (leaf-like structure) below a spikelet in the inflorescence (flower cluster) of grass Poaceae ( ), also called Gramineae ( ), is a large and nearly ubiquitous family (biology), family of monocotyledonous flow ...

s taper at their ends and have translucent margins. The lower glumes are one-nerved and long, and the upper glumes are three-nerved and long. The glabrous and slightly rough lemmas are long. The lemmas are hairier towards their edges and have five to seven veins. The awns are about the same length, long, and curve slightly. The

anther The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filament ...

s are long. The caryopses are as long as . The grass emerges in early winter and remains dormant until spring when heavy rainfall and higher temperatures stimulate growth. Plants flower from this period typically until May when

water stress Water is an inorganic compound with the chemical formula . It is a transparent, tasteless, odorless, and nearly colorless chemical substance. It is the main constituent of Earth's hydrosphere and the fluids of all known living organisms ( ...

inhibits the grass. Populations grow during periods of heavy rainfall and populations can be wiped out during extended periods of drought. The grass alters soil conditions and the

competition Competition is a rivalry where two or more parties strive for a common goal which cannot be shared: where one's gain is the other's loss (an example of which is a zero-sum game). Competition can arise between entities such as organisms, indi ...

brought about by the grass both negatively affect native plant populations, and the highly flammable nature of the grass produces wildfires in North American communities where fire was previously rare. Dry

s of the weed entangle themselves in animal hair and can tear at the

digestive tract The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the Digestion, digestive system that leads from the mouth to the anus. The tract is the largest of the body's systems, after the cardiovascula ...

s of foraging livestock.

Habitat and distribution

''Bromus madritensis'' is native to southern and western

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

but has been introduced and naturalized nearly worldwide. In

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

it is found primarily in the western

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

, in

Oregon Oregon ( , ) is a U.S. state, state in the Pacific Northwest region of the United States. It is a part of the Western U.S., with the Columbia River delineating much of Oregon's northern boundary with Washington (state), Washington, while t ...

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

, and

Arizona Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...

. The grass was brought to North America in 1848 and was naturalized by the 1890s. In its native range the grass grows in cultivated fields and

steppe In physical geography, a steppe () is an ecoregion characterized by grassland plains without closed forests except near rivers and lakes. Steppe biomes may include: * the montane grasslands and shrublands biome * the tropical and subtropica ...

s, and in North America it grows in waste areas, road verges, and disturbed areas, in both ranges primarily on dry stony or sandy soil. In California, the weedy grass occurs in areas disturbed by

wildfire A wildfire, forest fire, or a bushfire is an unplanned and uncontrolled fire in an area of Combustibility and flammability, combustible vegetation. Depending on the type of vegetation present, a wildfire may be more specifically identified as a ...

s. It grows from sea level to elevations of .

References

External links

*
Photos: ssp. ''rubens''
{{Taxonbar, from=Q163230 madritensis Flora of Europe Plants described in 1759 Taxa named by Carl Linnaeus Grasses of Lebanon