''Bromus'' is a large

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

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

, 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 group of wild and domesticated grasses of the genus ''Triticum'' (). They are cultivated for their cereal grains, which are staple foods around the world. Well-known wheat species and hybrids include the most widely grown comm ...

'' (wheat), ''

Hordeum ''Hordeum'' is a genus of annual and perennial plants in the grass family. The species are native throughout the temperate regions of Africa, Eurasia, and the Americas. Taxonomy Species Species include: * '' Hordeum aegiceras'' – Mongo ...

'' (barley) and ''

Secale ''Secale'' is a genus of the grass Poaceae ( ), also called Gramineae ( ), is a large and nearly ubiquitous family (biology), family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos, t ...

'' (rye).

Etymology

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

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

''bromos'', a borrowed word from the

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

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

Hippocrates Hippocrates of Kos (; ; ), also known as Hippocrates II, was a Greek physician and philosopher of the Classical Greece, classical period who is considered one of the most outstanding figures in the history of medicine. He is traditionally referr ...

''On Regimen in Acute Diseases'' 2.43, Dioscorides Medicus 2.94, '' Polemo Historicus'' 88) and '' Avena barbata'' (Theophrastus '' Historia Plantarum'' 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 (approximately 23.5° to 66.5° N/S of the Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ran ...

regions of the world, including

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

America 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 ...

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

and

Eurasia Eurasia ( , ) is a continental area on Earth, comprising all of Europe and Asia. According to some geographers, Physical geography, physiographically, Eurasia is a single supercontinent. The concept of Europe and Asia as distinct continents d ...

. 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 image:Hierarchical clustering diagram.png, 280px, Generalized scheme of taxonomy Taxonomy is a practice and science concerned with classification or categorization. Typically, there are two parts to it: the development of an underlying scheme o ...

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 a gonad in the female reproductive system that produces ova; when released, an ovum travels through the fallopian tube/ oviduct into the uterus. There is an ovary on the left and the right side of the body. The ovaries are end ...

. The leaf blades and sheaths, which comprise the

leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

can be hairless, sparsely hairy or hairy. The

inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

is a dense or open

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 ...

, 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 ...

s of some

Lepidoptera Lepidoptera ( ) or lepidopterans is an order (biology), order of winged insects which includes butterflies and moths. About 180,000 species of the Lepidoptera have been described, representing 10% of the total described species of living organ ...

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 ...

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 , commonly found in nature as quartz. In many parts of the world, silica is the major constituent of sand. Silica is one of the most complex and abundant f ...

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 th ...

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

erosion Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...

but such use must be cautiously controlled as most ''Bromus'' have the ability to spread, becoming invasive weeds. Cheatgrass ('' Bromus tectorum'') is a particularly troublesome weed across much of western North America (from southern

British Columbia British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...

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 ...

Taxonomy and systematics

Taxonomist In biology, taxonomy () is the science, scientific study of naming, defining (Circumscription (taxonomy), circumscribing) and classifying groups of biological organisms based on shared characteristics. Organisms are grouped into taxon, taxa (si ...

s 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 (''B. inermis'') flowers Bromus kalmii EPA-3.jpg, Arctic brome
''B. kalmii'' Bromus madritensis rubens in desert.jpg, red brome
''B madritensis'' ssp. ''rubens'' Bromus sitchensis 2689.JPG, Alaska brome
''B. rigidus'' Bromus secalinus2.jpg, rye brome (''B. secalinus'') flowers Bromus sterilis.jpeg, barren brome
''B. sterilis''

References

External links

Brome grasses UK

* {{Authority control Poaceae genera Grasses of Africa Grasses of Asia Grasses of Europe Grasses of North America Grasses of Oceania Grasses of South America Taxa named by Giovanni Antonio Scopoli