Arrhenatherum, commonly called Oat-grass or Button-grass, is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 with seven species and subspecies from the grass family Poaceae

Poaceae

The Poaceae is a large and nearly ubiquitous family of flowering plants. Members of this family are commonly called grasses, although the term "grass" is also applied to plants that are not in the Poaceae lineage, including the rushes and sedges...

. It grows in Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

 and the Mediterranean. Wild forms resemble Wild Oat (Avena

Avena

The oats are a genus of 10-15 species of true grasses . They are native to Europe, Asia and northwest Africa. One species is widely cultivated elsewhere, and several have become naturalized in many parts of the world...

) or Fescue (Festuca). Meadow Oat-grass is also found on some alvar

Alvar

An alvar is a biological environment based on a limestone plain with thin or no soil and, as a result, sparse vegetation. It is also known as a pavement barren although this term is also used for similar landforms based on sandstone. In the United Kingdom the exposed landform is called a limestone...

 formations such as the Stora Alvaret

Stora Alvaret

The Stora Alvaret is a limestone barren plain on the island of Öland, Sweden. Because of the thin soil mantle and high pH levels, a great assortment of vegetation is found including numerous rare species. Stora Alvaret has been designated as a World Heritage Site by UNESCO due to its...

 of Oland

Öland

' is the second largest Swedish island and the smallest of the traditional provinces of Sweden. Öland has an area of 1,342 km² and is located in the Baltic Sea just off the coast of Småland. The island has 25,000 inhabitants, but during Swedish Midsummer it is visited by up to 500,000 people...

, Sweden

Sweden

Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....

.

Oat-grass is a very common perennial

Perennial plant

A perennial plant or simply perennial is a plant that lives for more than two years. The term is often used to differentiate a plant from shorter lived annuals and biennials. The term is sometimes misused by commercial gardeners or horticulturalists to describe only herbaceous perennials...

 with yellowish root

Root

In vascular plants, the root is the organ of a plant that typically lies below the surface of the soil. This is not always the case, however, since a root can also be aerial or aerating . Furthermore, a stem normally occurring below ground is not exceptional either...

s. The shining stems

Plant stem

A stem is one of two main structural axes of a vascular plant. The stem is normally divided into nodes and internodes, the nodes hold buds which grow into one or more leaves, inflorescence , conifer cones, roots, other stems etc. The internodes distance one node from another...

 grow to a height of 1.50 m, but die off in winter. The leaves

Leaf

A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....

 are hairless with blunt ligules. The inflorescence

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. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...

 spreads into a panicle

Panicle

A panicle is a compound raceme, a loose, much-branched indeterminate inflorescence with pedicellate flowers attached along the secondary branches; in other words, a branched cluster of flowers in which the branches are racemes....

 with 2-flowered bisexual spikelets.

Species

• Arrhenatherum album: Tall Oat-grass
• Arrhenatherum calderae
• Arrhenatherum elatius
  Arrhenatherum elatius
  -Introduction:Arrhenatherum elatius, with the common names false oat-grass, tall oat-grass, tall meadow oat, onion couch and tuber oat-grass, is a perennial species of grass, common in the temperate regions of Europe....
  
  : False Oat-grass, Tall Oat-grass, Tall Meadow Oat
  • Arrhenatherum elatius var. bulbosum: Onion Couch, Tuber Oat-grass
  • Arrhenatherum elatius var. elatius: False Oat-grass, French Rye, Meadow Oat-grass
• Arrhenatherum kotschyii
• Arrhenatherum longifolium
• Arrhennatherum palaestinum
• Arrhenatherum pallens