TALL OAT GRASS (Arrhenatherum elatius (L.) Beauv.)
Plate 7; Seed, Plate 26, Fig. 12.
Other English names: Oat Grass, False Oat Grass, Meadow Oat Grass, Tall Meadow Oat Grass.
Botanical description: Tall Oat Grass is perennial with a short rootstock from which leafy stems and sterile shoots develop. Sometimes the rootstock is swollen and the shoots bulblike at the base. The rootstock being short, the shoots become crowded and the plant therefore grows in tufts. These are, however, rather loose. The stems are from two to five feet high, often knee-bent at the base, generally dark green. They are leafy to above the middle. The leaves are long and broad, rather soft in texture, and usually bright green, almost yellowish. When mixed with other grasses, Tall Oat Grass may be recognized by this peculiar colour. The flowers are in a spreading panicle, which somewhat resembles that of oats—hence the name Oat Grass. The general appearance of the spikelets is also similar to oats. Each spikelet contains two flowers which are very unlike. The lower one has only stamens, is consequently sterile, and its glume bears a long, bent awn; the glume of the upper one has generally no awn, both stamens and pistil are developed, and the flower is thus fertile. Each spikelet consequently produces only one grain. Rarely both flowers are awned and sometimes a third flower is developed above the two normal ones. Stamens and pistil are ready for fertilization at the same time. There is there-fore a chance for self-fertilization, although cross-fertilization is probably quite frequent.
Geographical distribution: Tall Oat Grass is indigenous to the greater part of Europe and to northern Africa and western Asia. It was introduced into North America from Europe.
Habitat: It grows in meadows and on hills, in open fields and in openings in woods, along seashores and on mountains.
Cultural conditions: Tall Oat Grass can be grown on almost any kind of soil, provided it is fairly moist. It does well on high, dry, gravelly soils, but will not make a satisfactory growth on very wet ground. It gives the best returns on light, moist loams and on clays not too stiff and wet. As the roots go deep, it will stand considerable drought. It is fairly winter hardy.