Weed Description: A
clump-forming summer annual with a seedhead that resembles a fox's tail. A weed of
many agronomic crops, turf, landscapes, and nurseries. Found throughout the United States,
especially on fertile soil.
are rolled in the bud, leaf sheaths are mostly without hairs, but the leaf blades have
many short hairs on the upper leaf surface and along the leaf margins. The ligule of
the seedlings is a fringe of hairs approximately 1/2 mm long, often very difficult to see
with the naked eye.
Roots: A fibrous root system.
Stems: Erect, round, usually without
hairs, reaching 3 to 4 feet in height.
Leaves: Leaf blades may reach 16
inches in length and 15 to 25 mm in width, and are generally covered with many small hairs
on the upper leaf surface, except near the leaf base. Auricles are absent and the
ligule is a fringe of hairs reaching 3 mm in length.
The seedhead is a cylindrical, bristly panicle that becomes drooping with maturity.
Spikelets are approximately 3 mm long, green, and each spikelet has 1-3
bristles that are 5-10 mm long.
Identifying Characteristics: Characteristic
foxtail-like seedhead that droops when mature and leaves with many hairs on the upper leaf
surface, which helps to distinguish this weed from both Green
Foxtail (Setaria viridis) and Yellow
Foxtail (Setaria glauca). Giant foxtail may be identified by the presence of
many short hairs on the upper surface of the leaf blades, unlike the other foxtails.
Additionally, giant foxtail is generally larger and has a nodding seedhead, unlike the