Yellow foxtail is an annual weed, reproducing by seeds. The stems are erect and 4.5 cm to 1 m tall. Plants may consist of many tillers causing the base to be highly branched. Leaf blades are smooth, 4 mm to10 mm wide to 30 cm long, with long hairs at the base and margin surface. The leaf sheath is smooth, 8 mm to 3.5 cm long x 1.2 cm wide, compressed, keeled and hairless.
The flowers are dense spike-like panicles with yellow bristles 3 cm to 10 cm in length.
Yellow foxtail grows in row crops, small grain crops and prefers warmer regions. This weed is a problem in spring seeded alfalfa stands, forage legumes, and grain crops.