Barley: Types and Description
Barley is an annual cereal of the grass family. It matures in a relatively short period of time and is therefore adapted to growing in a wide variety of environments. Barley species make up the genus Hordeum, which belongs to the family Poaceae, in the order Cyperales, class Liliopsida. Some of the wild species are weedlike and have only a slight similarity in appearance to cultivated barley.
H. vulgare, known as common barley, is cultivated in two- and six-rowed varieties, the small barley flowers (florets) occurring in groups of three on alternate sides of the plant's head (spike). In six-rowed barley all of the florets are fertile and produce seeds, thus creating six rows of seeds along the spike. In the two-rowed plants (formerly classified as a separate species, H. distichon), the outer florets of each group of three are sterile, leaving only one row of seeds on each side of the spike.
Each barley seed is enclosed in a strong outer covering (hull), which remains intact even during threshing. The naked barley seed within this hull is similar in shape to a kernel of wheat. The kernels of important varieties of barley are white or blue, but black-, red-, and purple-seeded varieties also exist.
Most barley varieties have a long beard (awn), which is part of the hull and extends 2 to 3 inches (5 to 7.6 cm) beyond the kernel. The awn breaks away from the hull during threshing and remains with the chaff and stems. In the older varieties the awns have a row of sharp projections on two edges; these projections are a source of discomfort to persons working with the mature crop and can become lodged in the mouths of livestock that feed on barley straw. Agricultural researchers have developed new varieties of barley by combining the favorable characteristics of imported grains—including a black-seeded, smooth-awned variety from Russia and a type of barley without awns (hooded) from Nepal—with desirable features of domestic ones. Some of the resulting smooth-awned varieties are called Glabron, Velvet, and Comfort. The hooded varieties are lower-yielding plants but are increasingly being grown.
The vegetative parts of the barley plant are very similar to those of wheat and oats. Barley may be distinguished by an ear-shaped appendage (auricle) at the base of the leaf. This auricle clasps about the stem and has pointed projections that overlap at the side opposite the leaf.