Description: This dioecious perennial grass has separate male (staminate) and female (pistillate) plants. There are also vegetative shoots without spikelets. The male plants are about 6-8" tall; they have unbranched culms with about 3-4 alternate leaves along the lower two-thirds of the culm. The culms are light green, glabrous, terete to somewhat flattened in cross-section, and mostly hidden by the sheaths. The leaf blades are up to 4" (10 cm.) long and 2.5 mm. across; they are greyish green or greyish blue, sparsely hairy or pubescent on both sides (upper & lower), and ascending to widely spreading. The open leaf sheaths are light greyish green, longitudinally veined, and mostly hairless, except toward the apex. The nodes are swollen, light green, and glabrous; the culm is purplish immediately above and below each node. At the junction of each sheath and blade, the ligule consists of a short tuft of curly white hairs. The vegetative characteristics of the female plants are similar to the male plants, except that their culms and leaf blades are much shorter.
The culm of each male plant terminates
in an inflorescence consisting of 2-3 staminate spikes. The typical staminate
spike is about 8-15 mm. (1/3–2/3") in length and about 4 mm. across. Each
of these spikes has about 6-12 spikelets that are arranged in 2 rows on one
side of the floral stalk (the spike's central axis). Each staminate spikelet
has a pair of glumes at its base and 2-3 lemmas that are arranged side-by-side.
One glume is about 3.0 mm. in length, while the remaining glume and lemmas are
about 4.0–4.5 mm. in length. The glumes and lemmas are linear-lanceolate
in shape and hairless. They are initially light green, but become light tan at
maturity. Disarticulation is above the glumes. The short culm of each female
plant terminates in a cluster of 2-3 pistillate spikelets that are joined
together at the base. These spikelets are largely hidden by the leaf blades.
The outer sides of each pistillate spikelet consist of a glume and a lemma that
are joined together at the edges, forming a bur-like structure. They are
similar in size and shape; each one becomes swollen and rounded toward the
middle and has 3 cleft pointed lobes at its apex. The blooming period usually
occurs during early to mid-summer. Each pistillate spikelet of the female
plants produces a single large seed. The root system is fibrous and
stoloniferous. In open areas, this grass readily spreads by its stolons to form
a soft turf.
Cultivation: The preference
is full sun, dry conditions, and barren soil. This species doesn't tolerate
competition from taller plants. It can adapt to a less ideal site with partial
sun, mesic conditions, or fertile soil if there is a regimen of regular mowing
(as occurs in lawns). Most vegetative growth occurs during the summer. Because
of its C4 metabolism and other characteristics, this grass has exceptional
drought resistance.
Range &
Habitat: Buffalo Grass is a rare plant in the natural areas of
Illinois. Some populations are thought to be native (particularly in central
& NW Illinois), while other populations have been introduced. These
introduced plants are either adventive from the Western states, or they have
escaped from local lawns where Buffalo Grass has been used as a turf grass.
Habitats include hill prairies, cemetery prairies, lawns, and barren waste
areas. In dry areas, this grass helps to bind the soil and prevent erosion by
wind or water. It is one of the dominant grasses of the shortgrass prairie in
the Great Plains.
Faunal
Associations: Several species of grasshoppers feed on the foliage of
Buffalo Grass (see Grasshopper Table); they include Ageneotettix
deorum (White-Whiskered Grasshopper), Arphia pseudonietana
(Red-Winged Grasshopper), Dissosteira carolina (Carolina Grasshopper),
Orphulella speciosa (Slantfaced Pasture Grasshopper), Phoetaliotes
nebrascensis (Large-Headed Grasshopper), and Spharagemon collare
(Mottled Sand Grasshopper). These observations have occurred primarily in other
states where Buffalo Grass is more abundant. In the shortgrass prairie of the
Great Plains, this grass is eaten by Buffalo and Pronghorn. It is also eaten by
other hoofed mammalian herbivores, including deer, horses, cattle, and other
livestock.
Photographic Location: A
lawn near Urbana, Illinois. A pistillate spike is dimly visible in the
background underneath the staminate spikes of the above
photograph.
Comments: During the
summer, this grass forms a green-grey or blue-grey turf that is attractive and
soft. However, it dies down during the winter. Buffalo Grass resembles the
shorter Bouteloua spp. (Grama grasses), including Bouteloua
gracilis (Blue Grama) and Bouteloua hirsuta (Hairy Grama). These
short grasses produce floral spikes that are shaped like small combs or
eyelashes. Unlike the Grama grasses, Buffalo Grass is dioecious and produces
separate staminate and pistillate spikes.