green foxtail
Family
PoaceaeScientific Name
Setaria viridis
Other Common Names:
green bristlegrass
Habit
Pants germinate in spring and compete with crops during summer. Seed production starts in mid to late summer. Reproduces by seed. Plants grow in clumps with a fibrous root system, but lack stolons or rhizomes.
Leaves
Leaves are light green and usually lack any hairs. Ligule is hairy and short (2mm). Leaves may reach 12 inches (304 mm) in length and 5-15mm in width.
Identifying Characteristics
Ligule is hairy, entire plant lacks hairs. Plants lack auricles and do not have stolons or rhizomes. Plants have a characteristic foxtail seed head. One easy way to distinguish from Giant and Yellow Foxtail, is its lack of hairs. However it is important to note the only other area with hairs is Green Foxtail's collar.
Flower Seed Head
A cylindrical bristly panicle on the end of a long, slender, naked stem. Seedhead is typically short (6 inches long & 1/3-2/3 inch wide) and does not nod. Spikelets are 3mm long with 1-3 bristles per spikelet which are 5-10mm long.
Seed Fruit
Seed are 3 to 5 mm long and covered with upper and lower sheath (palea and lemma) that have pronounced veins. Seed often have bristles that arise from the scar. These bristles may or may not be present.
Where Found
Typically found in cultivated areas following a tillage event. May occur in open areas such as the border of rock driveways, roadsides, and highly disrupted turfgrass.
Leaf Hair on Upper Surface
no hairs
Leaf Arrangement
rolled in bud
Mature Leaf Width
Varies:
less than 5 mm,
6 to 15 mm,
more than 15 mm
Stem
round
Seedhead
Varies:
bristly,
panicle
Life Cycle
summer annual
Auricle
not present
Ligule
hairy
Ligule Length
Varies:
1-2 mm,
2-3 mm
Plant Type
Grass