Barnyard Grass (Echinochloa crus-galli). This strong summer annual matures at ½ to 6 feet tall and often spreads from its base to form large clumps. The leaves are 4 to 20 inches long and ¼ to ¾ inches wide. Flowering occurs along the top 3 to 10 inches of the stem. Flowering branches are 1 to 2 ¼ inches long with short green or purple spiklets 1/8 inch long with bristles up to 1 ½ inches long. A single plant can produce 40,000 of the pale yellow shiny seeds. A. Spikelet spread open. B. Two spikelets with short and long awns. C. Grain.