Ontario Weeds: Green foxtail
Table of Contents
- Other Names
- General Description
- Stems and Roots
- Flowers and Fruit
- Similar Species
- Related Links
Name: Green foxtail, Setaria viridis
Other Names: sétaire verte, Bottle
brush, Bottle grass, Bristle grass, Foxtail millet, Millet, Pigeon
grass, Wild millet, mil sauvage
Family: Grass Family (Gramineae)
General Description: Annual, reproducing
only by seed.
Photos and Pictures
Green foxtail (A - plants; B - leaf-base with hairy
ligule and ciliate margins of leaf sheath).
Green foxtail. A. Plant with stem folded
twice. B. Leaf bse. C. Spike. Bristly foxtail. D. Leaf-base.
E. Spike. F. Cluster of 3 spikelets and 6 bristles with backward-pointing
Stem and leaf-base characteristics of a typical grass.
Stems & Roots: Stems erect or
spreading, 10-100cm (4-40in.) tall or occasionally taller, usually
round in cross-section but occasionally much flattened; leaves and
leaf sheaths of very young plants often densely hairy but with upward-pointing
hair; upper leaf blades and leaf sheaths mostly without hair; margins
and both surfaces of leaf blades rough with very fine forward-pointing
barbs; leaf sheath split with overlapping margins, both margins
being fringed with a band of short hair; ligule a fringe of hair
1.5-2mm (1/16-1/12in.) long; no auricles.
Flowers & Fruit: Inflorescence
a very dense spike 1-15cm (2/5-6in.) long and 0.6-2.0cm (1/4-4/5in.)
wide, usually straight and erect or rarely somewhat curved, the
larger ones sometimes with short branches up to 1cm (2/5in.) long,
and covered with short green to slightly purplish bristles which
give the inflorescence a bottle-brush appearance; the bristles have
microscopic forward-pointing barbs that allow the seed head to be
dragged downwards but not pushed upwards over the skin or a rough
surface. Spikelets about 2mm (1/12in.) long by 1mm (1/25in.) wide;
each contains a single fertile floret ("seed" or "grain"),
that is rounded on one surface but flattened on the other, finely
cross-ridged (seen only with magnification), and dull yellowish-green
with brownish spots. Flowers from July to August.
Habitat: Green foxtail is very common
and widespread throughout all agricultural regions of Ontario. It
grows well in all soil textures and occurs in cultivated lands,
waste places, roadsides, gardens and occasionally lawns.
Similar Species: It is distinguished from
foxtail by its green or purple bristles, the absence of long,
kinky hair on the upper surface of the leaf blade near the stem,
the presence of a fringe of hair on both margins of the leaf sheath,
and its somewhat smaller grains or seeds. It is distinguished from
foxtail by its denser, more continuous spike whose bristles
do not cling when sliding the fingers upwards on it. It is distinguished
foxtail by its usually shorter stature, its shorter, thinner
and usually erect inflorescence (rarely curved or nodding) and the
absence of a covering of short hair on leaf surfaces in the middle
and upper parts of the plant.
... on general Weed
... on weed identification, order OMAFRA
Publication 505: Ontario Weeds
... on weed control, order OMAFRA
Publication 75: Guide To Weed Control
to the Ontario Weeds Gallery |