''Bromus'' is a large

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

grasses Poaceae () or Gramineae () is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos and the grasses of natural grassland and species cultivated in lawns and ...

, 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 to 400, but plant taxonomists currently recognize around 160–170 species. ''Bromus'' is part of the cool-season grass lineage (subfamily Pooideae), which includes about 3300 species. Within Pooideae, ''Bromus'' is classified in tribe Bromeae (it is the only genus in the tribe). ''Bromus'' is closely related to the wheat-grass lineage (tribe Triticeae) that includes such economically important genera as ''

Triticum Wheat is a grass widely cultivated for its seed, a cereal grain that is a worldwide staple food. The many species of wheat together make up the genus ''Triticum'' ; the most widely grown is common wheat (''T. aestivum''). The archaeologica ...

'' (wheat), ''

Hordeum ''Hordeum'' is a genus of annual and perennial plants in the grass family. They are native throughout the temperate regions of Africa, Eurasia, and the Americas. One species, ''Hordeum vulgare'' (barley), has become of major commercial importan ...

'' (barley) and ''

Secale ''Secale'' is a genus of the grass tribe Triticeae, which is related to barley (''Hordeum'') and wheat (''Triticum''). The genus includes cultivated species such as rye (''Secale cereale'') as well as weedy and wild rye species. The most well kn ...

'' (rye).

Etymology

The generic name ''Bromus'' is derived from the

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

''bromos'', a borrowed word from the

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...

(). and mean ''oats'', but seems to have referred specifically to '' Avena sativa'' (

Hippocrates Hippocrates of Kos (; grc-gre, Ἱπποκράτης ὁ Κῷος, Hippokrátēs ho Kôios; ), also known as Hippocrates II, was a Greek physician of the classical period who is considered one of the most outstanding figures in the history of ...

''On Regimen in Acute Diseases'' 2.43, Dioscorides Medicus 2.94, ''

Polemo Historicus Polemon (or Polemo) is the name of eminent ancient Greeks: Philosophers *Polemon (scholarch), the head of the Platonic Academy from 314–269 BC *Polemon of Athens, a 2nd-century BC Stoic philosopher, also referred to as Polemon of Ilium *Polemon o ...

'' 88) and ''

Avena barbata ''Avena barbata'' is a species of wild oat known by the common name slender wild oat. It has edible seeds. It is a diploidized autotetraploid grass (2n=4x=28). Its diploid ancestors are ''A. hirtula'' Lag. and ''A. wiestii'' Steud (2n=2x=14), whi ...

'' (Theophrastus ''

Historia Plantarum Historia may refer to: * Historia, the local version of the History channel in Spain and Portugal * Historia (TV channel), a Canadian French language specialty channel * Historia (newspaper), a French monthly newspaper devoted to History topics * ...

'' 8.9.2, Pseudo-Dioscorides 4.137). The generic name comes from , a native Latin word for "oats" or "wild oats".

Description

''Bromus'' species occur in many habitats in

temperate In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout t ...

regions of the world, including

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

America The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

and

Eurasia Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelago a ...

. There are considerable morphological differences between some species, while the morphological differences between others (usually those species that are closely related) are subtle and difficult to distinguish. As such, the

taxonomy Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...

of the genus is complicated. ''Bromus'' is distinguished from other grass genera by a combination of several morphological characteristics, including leaf sheaths that are closed (connate) for most of their length, awns that are usually inserted subapically, and hairy appendages on the

ovary The ovary is an organ in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus, where it may become fertilized by a sperm. There is an ovary () found on each side of the body. ...

. The leaf blades and sheaths, which comprise the

leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

can be hairless, sparsely hairy or hairy. The

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

is a dense or open

panicle 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 panicle are of ...

, usually drooping or nodding, sometimes spreading (as in Japanese brome, ''B. japonicus'').

Ecology

The

caterpillar Caterpillars ( ) are the larval stage of members of the order Lepidoptera (the insect order comprising butterflies and moths). As with most common names, the application of the word is arbitrary, since the larvae of sawflies (suborder Sym ...

s of some

Lepidoptera Lepidoptera ( ) is an order (biology), order of insects that includes butterfly, butterflies and moths (both are called lepidopterans). About 180,000 species of the Lepidoptera are described, in 126 Family (biology), families and 46 Taxonomic r ...

use ''Bromus'' as a foodplant, such as the chequered skipper (''Carterocephalus palaemon'').

Uses

''Bromus'' species are generally considered to have little economic value to humans, at least in present times. ''Bromus mango'' was historically cultivated in Chile and Argentina by indigenous peoples, who used it both as fodder and food. The Tarahumara Indians in northern Mexico use the grains of some native ''Bromus'' species to aid fermentation in making one of their cultural beverages. As names like poverty brome ( ''B. sterilis'') and ripgut brome (''B. diandrus'') attest, some species are not very useful as

fodder Fodder (), also called provender (), is any agriculture, agricultural foodstuff used specifically to feed domesticated livestock, such as cattle, domestic rabbit, rabbits, sheep, horses, chickens and pigs. "Fodder" refers particularly to food g ...

because their leaves sclerotize quickly and may even be harmful to livestock due to the high

silica Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is one ...

content. Others, such as meadow brome ('' Bromus riparius''), native to parts of Russia, are planted as forage in the Great Plains of North America. Brome grasses are not usually grown as

ornamental plant Ornamental plants or garden plants are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars that i ...

s due to most species' nondescript appearance. Some are useful to prevent

erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distin ...

but such use must be cautiously controlled as most ''Bromus'' have the ability to spread, becoming

invasive weed An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...

s. Cheatgrass (''

Bromus tectorum ''Bromus tectorum'', known as downy brome, drooping brome or cheatgrass, is a winter annual grass native to Europe, southwestern Asia, and northern Africa, but has become invasive in many other areas. It now is present in most of Europe, southe ...

'') is a particularly troublesome weed across much of western North America (from southern

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

Taxonomy and systematics

Taxonomists have generated various classification schemes to reflect the morphological variation that is seen in ''Bromus''. In North America, five morphologically similar groups of species, called sections, are generally recognized: '' Bromus'', '' Genea'', '' Ceratochloa'', '' Neobromus'', and '' Bromopsis''. Sections ''Bromus'' and ''Genea'' are native to the Old World (Eurasia), but many species are introduced into North America. Sections ''Bromopsis'', ''Neobromus'', and ''Ceratochloa'' have several native species in North America.

Selected species

Gallery

Bromus inermis detail.jpeg,

awnless brome ''Bromus inermis'' is a species of the true grass family ( Poaceae). This rhizomatous grass is native to Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the ...

(''B. inermis'') flowers Bromus kalmii EPA-3.jpg, Arctic brome
''B. kalmii'' Bromus madritensis rubens in desert.jpg,

red brome ''Bromus madritensis'' is a species of brome grass known by the common name compact brome. The specific epithet ''madritensis'' refers to Madrid, Spain. It has a diploid number of 28. There are two subspecies: *''Bromus madritensis'' subsp. ''ma ...

''B madritensis'' ssp. ''rubens'' Bromus sitchensis 2689.JPG, Alaska brome
''B. rigidus'' Bromus secalinus2.jpg,

rye brome ''Bromus secalinus'' is a species of bromegrass known as rye brome. The specific epithet ''secalinus'' is Latin, meaning "rye-like". The fruits are hard, rounded glumes that appear superficially similar to the rye grain, which gives the brome i ...

(''B. secalinus'') flowers Bromus sterilis.jpeg, barren brome
''B. sterilis''

References

External links

Brome grasses UK

* {{Taxonbar, from1=Q147621, from2=Q4895613 Poaceae genera Grasses of Africa Grasses of Asia Grasses of Europe Grasses of North America Grasses of Oceania Grasses of South America