Hordeum jubatum, with common names foxtail barley, bobtail barley squirreltail barley, and intermediate barley, is a perennial plant species in the grass family Poaceae.
Foxtail barley (Hordeum jubatum) propagates by seed. It is known for its ability to tolerate saline soils but is capable of productive growth on soil types ranging from loamy to clayey soils with pH's of 6.4 to 9.5.
Foxtail barley is a prolific seed producer, with each plant capable of producing upwards of 200 seeds. Seeds are elliptical, yellowish-brown and about a 0.25 inches (0.64 cm) long with four to eight awns. The seeds have sharp, backwards pointing barbs. Seed is dispersed by wind, machinery and animals and germinates in the cooler temperatures of the spring or fall. Seed germinating in the fall can overwinter and resume growth in early spring, giving Foxtail barley a competitive advantage over many crops. Germination is inhibited by warm temperatures and seeds require a period of darkness for germination to occur. Foxtail barley is a shallow-rooted plant with germination occurring at soil depths not greater than 3 inches (7.6 cm). The seedling of foxtail barley first appears as thin, vertical leaves covered in short, dense hairs. The leaves have prominent venation and rough margins, while auricles are absent or elemental and the membranous ligule is very short with fine hairs.
Foxtail barley is a fibrous-rooted, densely tufted grass that grows from 30–100 centimetres (12–39 in) tall and is erect or reclining at the base. The stems are erect and smooth and the leaf sheaths are split and hairy. The inflorescence of the mature plant is a dense, long-awned nodding spike with greenish or purplish colouring. The jointed rachis breaks into sharply pointed segments with three spikelets composing each segment. Only the central spikelet has one creamy coloured seed while each segment has seven awns with upward pointing barbs. These awns are up to 3 inches (7.6 cm) long and become easily attached to animals, clothing, machinery, etc. Leaf blades are slender and a greyish-green colour.