Arrhenatherum is a type of grass that is native to Europe, Western Asia, and Northern Africa; it is also found as an introduced species in many other parts of the world and seems to do particularly well in temperate regions. This grass gets its name from the Greek words arrhen, which means "male," and ather, which means "spike beard." The grass is also known as Avena elatior; in Latin, elatus means high or tall. More commonly known as oat grass or button grass, these grasses are perennials from the family Poaceae or Pooideae, and have straight stems that can grow up to 23.62 inches to 70.86 inches (60 cm to 180 cm) in height.
The oat grass stems are yellowish-green with finely textured leaves that are a variegated white or green. The leaves are usually 12 inches to 14 inches (30.48 cm to 35.56 cm) in length. The flowers, which appear between August and September, are 20 inches (50.8 cm) in size and are arranged in bisexual pairs on long stems. The plant roots are yellowish in color. The grass dies in the winter and new growth appears in the spring.
The two subspecies of this grass are the Arrhenatherum elatius and the Arrhenatherum bulbosum, which is also known as Arrhenatherum tuberosum or tuber oat grass. This latter variety, which spreads quickly from the corms or bulbs at the stem base, can be problematic as a weed. The first variety is commonly found growing in prairies, pastures and along roadsides, and is generally non-invasive. It is, in fact, cultivated as a nutritious crop for cattle feed in some areas; these grasses have a high calcium and phosphorus content. Oat grass has a bitter taste, however, which makes it off-putting as a grazing crop; it seems to become more palatable to the cattle after it has been harvested and dried to form hay.
Agricultural researchers are interested in using oat grass, particularly the Arrhenatherum elatius variety, to produce hardy varieties of the oat crop. Unlike oat plants, which tend to get damaged by frost, oat grass is quite capable of surviving extremely cold weather conditions. By introducing the oat grass germ into oat plants, the latter can perhaps be made equally resilient.
These grasses can also be used for decorative effect in gardens. As they grow in thick clumps, it is best to plant them at distances of 6 inches to 16 inches (15.24 cm to 40.64 cm) from each other. Arrhenatherum grows well in cool areas that have partial to full shade and a moist or well-drained soil. It will not thrive under hot and dry conditions.