Green Foxtail Setaria viridis (L.) Beauv. [SETVI]

General Description: a clump-forming summer annual, with ascending culms reaching 1 m in height, with characteristic bottle-brush or foxtail-like seedheads.

Seedling:  The first blade is linear, about 7 times longer than wide and opens parallel to the ground.  Leaves are rolled in the bud; auricles are absent, and the ligule is a fringe of hairs arising from a membranous base about 0.5 mm long.  Blades of young seedlings are 4.5 to 8 cm long and 3 to 5 mm wide, smooth on the lower and upper surfaces.  The margins are smooth or slightly rough, and the blade is keeled in the lower portion.  Sheath is smooth and compressed.  The collar is green and smooth.

Mature Plant:  Ligule is a fringe of hairs about 1 mm long.  Leaf blades are 30 cm long by 4 to 10 mm wide, keeled, and have long wispy hairs only on the upper surface at the base.  Sheath is smooth, compressed, often reddish at the base, and has a prominent midvein.  The collar is narrow, light green or yellowish, and smooth.

Flowers and Fruit:  Blooms in mid to late summer.  The seedhead is a coarse bristly spike-like panicle, 2 to 15 cm long and 1 cm wide.  The mature seedhead is present from late summer through autumn.  Spikelets are about 3 mm long, and each spikelet is subtended by 5 or more bristles.  Bristles are about 10 mm long and greenish at maturity.  Seeds are 2 to 3 mm long, ridges, and yellow.

Distribution:  Found in the eastern United States.

Crops Affected:  Corn, Soybean, Tobacco and Vegetable Crops

Animal Poisoning:  None

Similar Species:  Giant foxtail and yellow foxtail closely resemble yellow foxtail in general characteristics:  ligule, habitat, growth habit, and reproductive characteristics.