''Arrhenatherum'', commonly called oatgrass or button-grass, is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

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 ...

n and

North Africa North Africa, or Northern Africa is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region, and it is sometimes defined as stretching from the Atlantic shores of Mauritania in ...

n plants in the grass family.

Description

Wild forms can resemble

wild oat ''Avena'' is a genus of Eurasian and African plants in the grass family. Collectively known as the oats, they include some species which have been cultivated for thousands of years as a food source for humans and livestock. They are widespread ...

(''Avena'') or fescue (''Festuca''). Oatgrasses are very common

perennial A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wid ...

s with yellowish

root In vascular plants, the roots are the organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often below the su ...

s. The shining stems grow to a height of 1.5 meters, but die off in winter. The leaves are hairless with blunt ligules. The

inflorescence An inflorescence is a group or cluster of flowers arranged on a Plant stem, stem that is composed of a main branch or a complicated arrangement of branches. Morphology (biology), Morphologically, it is the modified part of the shoot of sperma ...

is a panicle with two-flowered bisexual spikelets. ; Species * '' Arrhenatherum album'' - tall oatgrass - Mediterranean from Portugal to Cyprus * '' Arrhenatherum calderae'' - Tenerife in Canary Islands * '' Arrhenatherum elatius'' - false oatgrass, tall oatgrass, tall meadow oat - Eurasia + North Africa from Iceland to Canary Islands + Kazakhstan; naturalized in East Asia, Australia, New Zealand, the AmericasRosengurtt, B., B. R. A. Maffei & P. I. Artucio. 1970. Gramíneas Uruguayas –vii 1–489. Universidad de la República, Montevideo * '' Arrhenatherum kotschyii'' - Turkey, Caucasus, Syria, Lebanon, Palestine, Jordan, Iraq, Iran, Afghanistan * '' Arrhenatherum longifolium'' - France, Spain, Portugal, Morocco * '' Arrhennatherum palaestinum'' - eastern Mediterranean from Greece to Iraq * '' Arrhenatherum pallens'' - Portugal ; formerly included numerous species now considered better suited to other genera: '' Avenula Danthoniastrum Duthiea

Helictochloa ''Helictochloa'' is a genus of Eurasian, North African, and North American plants in the grass family. ; Species See also * List of Poaceae genera The true grasses (Poaceae) are one of the largest plant families, with around 12,000 spec ...

Helictotrichon Sphenopholis''

References

{{Taxonbar, from=Q157689 Pooideae Poaceae genera Taxa named by Palisot de Beauvois