An Illustrated Guide to ARIZONA WEEDS
The University of Arizona Press
BARNYARDGRASS-Echinochloa crusgalli (L.) Beauv.
DESCRIPTION-A stout summer annual, 1/2 to over 4 feet high, which reproduces only by seed. It is often spreading and prostrate at the base, rooting at the lower nodes, sometimes forming large clumps.
The hairless leaves are dense, with blades 4 to 20 inches long, and 1/4 to 3/4 inch broad. The flowering tops are 3 to 8 or 10 inches long, with the erect branches 1 to 2 1/4 inches long.
The green or purplish spikelets, about 1/8 inch long (excluding the bristle when present), are densely and irregularly crowded on the branches, and almost without stalks. They typically are stiff hairy and short awned to sharp pointed at the tip, but sometimes ending in a bristle up to 1 1/2 inches long.
The pale yellow, shiny grain is flat on one side and round on the other. A single plant has been estimated to produce as many as 40,000 grains.
DISTRIBUTION-Barnyardgrass is a European introduction that has become a most troublesome weed in moist soil in all agricultural areas in the state. It is common in irrigated fields, orchards, pastures, roadside swales, reservoirs, ditches, and streams throughout most of Arizona; 100 to 7,000 feet elevation; flowering June to October. The name "crabgrass" should not be applied to this grass since that is the accepted name for Digitaria spp.
Copyright (c) 1972 The Arizona Board of Regents