Source: Idaho's Noxious Weeds by Robert H. Callihan & Timothy W. Miller
BACKGROUND
Jointed goatgrass (Aegilops cylindrica) is a native of southern Europe and western Asia. It is so closely related to wheat that both species can interbreed. It is difficult to distinguish from wheat until spikesA narrow, nonspreading inflorescence appear. It spreads exclusively by seed. Jointed Goatgrass grows best in cultivated fields, but it apparently can also invade grasslands.
DESCRIPTION
Jointed goatgrass is a winter annualPlant that germinates, flowers, seeds, and dies during one growing season, but about 5 percent of a population may be spring annuals. Leaves are grasslike, up to a ½ inch wide, and have evenly spaced fine hairs along the leaf edges and down the sheath opening. The liguleThe structure at the collar of a grass leaf between the sheath and the stem is short and membranous; auricles are short and hairy. Stems can grow up to 4 feet tall and are tipped with slender, cylindrical spikesA narrow, nonspreading inflorescence that appear to be a series of joints stacked on top of each other. Reddish to straw-colored spikes emerge in May to June, and uppermost joints are tipped by straight awnsSlender bristle at the tip of grass seed structure. Up to 3 "seeds" are enclosed in each joint.
DISTRIBUTION
-Jointed goatgrass is found in all major United States winter wheat production regions--from Texas to South Dakota and eastern Montana, and in portions of the Northwest and Utah.
CONTROL
No biological control agents are available for jointed goatgrass, and no herbicides are available that can selectively control it in winter wheat; spring tillage and general grass killers provide excellent control.