jointhead arthraxon
Family
PoaceaeScientific Name
Arthraxon hispidus
Other Common Names:
small carpgrass
hairy joint grass
joint-head grass
Synonyms (former Scientific Names):
Phalaris hispida
Arthraxon ciliaris
Habit
graminoid
Leaves
Leaves are broad and taper to a point, approximately 2 1/2 inches long by 3/4 inches wide. Leaf bases encircle the sheath and have conspicuous hairs along the margins.Leaves are without auricles and have a thin membranous ligule (often with hairs) that is from 1 to 2 mm long.
Identifying Characteristics
A low-growing annual grass with short, wide leaves.Jointhead arthraxon is primarily a weed of pastures, hay fields, and ditches. A low-growing grass with short, wide leaves with bases that encircle the stem and have hairs along the margins. This weed may be confused with Deer-Tongue Grass, but has spikelets instead of a panicled seedhead like that of deer tongue grass. Additionally, the leaves of deer-tongue grass are generally much longer than those of jointhead arthraxon, and the stems of deer-tongue grass do not root at the nodes like those of jointhead arthraxon.Jointhead arthraxon may also be confused with Common or Asiatic Dayflower (Commelina communis), which also has broad grass-like leaves and a prostrate growth habit. The two can be distinguished by the presence of a distinct ligule on jointhead arthraxon, which is not present on common or asiatic dayflower.
Flower Seed Head
Many spikelets that resemble 'fingers'
Where Found
found primarily in the piedmont areas of North Carolina, Virginia, Georgia, Florida, Alabama, Mississippi, and Tennessee.
Leaf Hair on Upper Surface
hairs from base to tip
Leaf Arrangement
rolled in bud
Mature Leaf Width
Varies:
less than 5 mm,
6 to 15 mm
Stem
round
Seedhead
spike
Life Cycle
summer annual
Auricle
not present
Ligule
Varies:
membrane,
hairy
Ligule Length
Varies:
less than 1 mm,
1-2 mm,
2-3 mm
Plant Type
Grass