small carpgrass (Arthraxon hispidus)
Arthraxon ciliaris P. Beauv. var. cryptatherus Hack.
Arthraxon hispidus (Thunb.) Makino var. cryptatherus (Hack.) Honda
Phalaris hispida Thunb.
TAXONOMY: The currently accepted scientific name for small carp-
grass is Arthraxon hispidus (Thunb.) Makino.
NATIVE STATUS: Introduced, United States.
GENERAL BOTANICAL CHARACTERISTICS: Small carpgrass is
a low-growing creeping annual grass in the Grass Family that grows to a
height of 1.5 feet. The ovate to lanceolate leaf blades are 0.75-2.75 inches
in length and 0.2-0.6 inches in width. There are hairs along the margins of
the leaf blades. The heart-shaped (cordate) bases of the leaves encircle the
sheath. The individual flowers, or spikelets, are arranged in multiple spike-
like racemes, averaging about 1½ inches long, that terminate the stems.
The stems develop roots at the lower nodes. The seeds are slender and
yellowish in color, measuring 1/6-inch long.
REGENERATION PROCESS: Small carpgrass propogates itself by
seeds that can be dispersed by moving water.
HABITAT TYPES: Small carpgrass is often found in moist pastures and
fields, shaded upland woods, floodplain forests, stream banks, along shore-
lines, roads and trails where soils remain moist.
SITE CHARACTERISTICS: Small carpgrass prefers sunny moist hab-
SEASONAL DEVELOPMENT: Small carpgrass flowers appear from September to October.
GENERAL DISTRIBUTION: Small carpgrass occurs throughout the
eastern portion of the United States, from Florida to the lower New Eng-
land states and westward to Texas north to Nebraska. It does not occur
in upper mid-West, northern Plains, far southwest, Rocky Mountain
states or most of the Pacific coast states (except Oregon). It does not
occur in Canada.
SKY MEADOWS DISTRIBUTION:
Grass specimens can be found on trails marked in red.
Appalachian Trail/Old Trail
South Ridge/North Ridge
Rolling Meadows/ Lost Mountain
The specific distribution of small carpgrass has not been determined.
IMPORTANCES AND USES: Small carpgrass was first observed in
Virginia in 1930s and may have been accidentally introduced. It can form
dense stands, particularly along shorelines that may threaten native vege-
tation. Jointhead grass often occurs with another highly invasive annual
grass species, Japanese stilt grass (Microstegium vimineum).
Crooked Run Valley