Virginia Tech Weed Identification Guide

Jointhead Arthraxon: Arthraxon hispidus

arthraxon6-28.jpg (180939 bytes) Weed Description:  A low-growing annual grass with short, wide leaves.  Jointhead arthraxon is primarily a weed of pastures, hay fields, and ditches found primarily in the piedmont areas of North Carolina, Virginia, Georgia, Florida, Alabama, Mississippi, and Tennessee.
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.

Flowers:  Many spikelets that resemble 'fingers'.

arthraxon6-28b.jpg (103127 bytes)
arthraxon6-28d.jpg (124792 bytes) Sheaths: Low-growing, branching and rooting at the lower nodes.  Sheaths are without hairs.

Roots:  A fibrous root system with sheaths that root at the nodes.

Identifying Characteristics:  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. arthraxonhispidus2.jpg (139611 bytes)