Description: Goose Grass is an introduced summer annual about ½–2' tall that is tufted at the base, sending up multiple ascending culms with alternate leaves. The culms are green, glabrous, and and somewhat flattened; they are mostly hidden by the sheaths. The leaf blades are up to 10" long and 1/3" across; they are medium to dark green, glabrous (especially while young), and either flat or indented in the middle. The leaf sheaths wrap loosely around the culms and are somewhat flattened; they are medium green, finely veined, and mostly glabrous. The apex of each sheath near the ligule often has long hairs that are white and cobwebby. Each ligule has a strip of short white hairs.
Each culm produces a whorl or dense
cluster of 2-6 floral spikes at the apex of a long stalk; there may be 1 or 2
individual spikes that are lower on the stalk. Each floral spike is about 3-4"
long, consisting of 2 dense rows of spikelets along its rachilla (branchlet of
the spike). Each floral spike is stiff and more or less straight; its rachilla
is green and glabrous. Each spikelet consists of 3-7 florets and their scales
(glumes and lemmas). The scales are arranged in two ranks and are appressed
together; the 2 sterile glumes are located at the bottom of each spikelet. The
scales are lanceolate, keeled, and thin-textured. They are initially green and
glabrous, but become shiny and silvery while the florets are blooming; later
they turn brown. The first glume is about 2–2.5 mm. long, the second glume
is about 3 mm. long, and the fertile lemmas (above the glumes) are about
3–3.5 mm. long. The blooming period occurs primarily during the summer;
however, some plants may bloom during the early fall. The small grains are
1.0–1.5 mm. long, dark brown, oblongoid, rough-textured, and indented on
one side; each grain has several fine ridges along its outer margin. The root
system is fibrous. This grass spreads by reseeding itself.
Cultivation: Typical growing conditions are full to
partial sun and moist to slightly dry soil that consists of loam, clay-loam, or
rocky material. Goose Grass is often found in heavy compacted soil; it is weedy
and aggressive.
Range &
Habitat: Goose Grass is common in most areas of Illinois, although
it is apparently less common or absent in rural areas in the northern half of
the state (see
Distribution
Map). This grass was introduced from Eurasia and it tends to be more common
in areas with warm climates. Habitats include lawns and gardens, cracks in city
sidewalks and pavement, edges of buildings, vacant lots, areas along railroads
and roadsides, fields, and waste areas. Less often, Goose Grass is found in
very degraded floodplain areas where there is scant ground vegetation. It is a
typical weed of disturbed urban areas.
Faunal
Associations: There is little available information for this species
about floral-faunal relations in the Midwest. The caterpillars of the skipper
Atalopedes campestris (Sachem) feed on the foliage. Mammalian herbivores
can eat this grass in limited amounts without ill-effects. Birds apparently
make little use of the seeds, at least in the Midwest.
Photographic Location: A crack in a city sidewalk in
Urbana, Illinois.
Comments: Goose
Grass superficially resembles one of the Digitaria spp. (Crabgrasses)
because of the finger-like spikes of its inflorescence and its habit of growth,
but it is actually quite different. The foliage of Goose Grass is dark green
and shiny, while the foliage of Crabgrass is dull medium green. The spikelets
of Goose Grass, if they are examined carefully, will be found to have multiple
overlapping scales and florets (typically 3-7 florets per spikelet). These
spikelets are initially shiny and silvery, but they later turn brown. In
contrast, each spikelet of Crabgrass has only a single floret and fewer scales.
The finger-like spikes of Crabgrass are more narrow than those of Goose Grass,
and they are usually green or reddish green and less shiny. The seeds of Goose
Grass have been used as a source of flour in the Middle East and
Africa.