by Lisa Taylor,
Native Plants Class
Common names: Blue grama, Blue grama grass, Eyebrow grass
Family: Poaceae
Synonymy: Nom, Bot. Ed. 2. 1: 219. 1840. Based on Chondrosium
gracile H.B.K.
Chondrosium gracile H.B.K., Nov. Gen. et Sp. 1: 176. pl. 58.
1816. Mexico, Humboldt and Bonpland (3).
Etymology: The genus Bouteloua is named for Claudia Boutelou,
a professor of agriculture at a university in Madrid, Spain. The specific
epithet, gracilis, is Latin for slender or graceful. The Navajo name
for Blue grama is Tl'oh nástasì and means "bent grass"
(4)
Identification
Growth form: Perennial bunchgrass growing to 25-70 cm in height
(1). It tends to be lower growing and mat-forming in its northern regions
and more tufted and taller in southern locations (2). Its comblike spikes
are distinctive, face downward and can be dark purple and straight to
light brown and curled, depending on the time of year (4).
Roots: Short, stout rhizomes; adventitious roots (1, 2).
Stem: Culm height can reach 25-70 cm (1). Sheaths are mostly
rounded, and ligules are often a fringe of short hairs (2).
Leaves: Relatively broad (for a grass), primarily basal leaves
(1) with blades 2.5 mm wide or less; usually flat or slightly curved
inward; ligules a fringe of short hairs.
Inflorescence/flowers: Panicoid inflorescences (1) of 1-3 (occasionally
4) spikes branching from the culm (2). Spikes are 2.5-5.0 cm long, spreading
at maturity and contain up to 80 spikelets in two rows on one side of
the rachis (3). Each spikelet is sessile, contains one fertile floret
~ 5mm long and is surrounded by an awned palea and lemma (3).
Fruit: The fruit is a caryopsis
Similar species: Genetic variation appears most extensive in
the southwest, suggesting this was the origin of grama grasses (1).
Related species are both perennials and annuals important as forage
in short grass regions of the Great Plains and/or the Southwest and
include the gramas: B. hirsute (Hairy grama), B. eriopoda
(Black grama), B. rothrockii (Rothrock grama), B. Barbata
and B. parryi (Six-weeks gramas), B. curtipendula
and B. trifida (3).
Ecology
Life history: Blue grama is a perennial.
Native/introduced: Native
Photosynthetic pathway: C4 (2)
Phenology: Blue grama is a warm-season grass (1) that grows from
June through November (4) and flowers from July through October (2).
Distribution: Blue grama has one of the most widespread distributions
of all the gramas. It is adapted to many soil types and habitats (2)
to include grasslands, desert shrublands, woodlands, and forests. It
is found in the short-grass region from Texas to Canada and in desert
grasslands of the Southwest (1). It is usually found at elevations between
4,000-8,500 feet (2, 4). In the southern part of its extent, it can
occur in almost pure stands, but tends to become less dominant in more
northern regions (1). Blue grama has also been reported in some eastern
states and in South America, where it was probably introduced (2).
Uses
Blue grama is an important pasture grass. It can withstand heavy grazing
pressure and drought conditions and is rated one of the best forage
species in the Southwest (2, 3). It is a major feed for horses, sheep,
goats and cattle. Medicinally, Blue grama can be used to heal cuts by
placing the chewed root on a wound. The entire plant can also be made
into a beverage to relieve postpartum pain. The Navajo also use the
root in 'life medicine' mixtures (4).
References
1. Barnes,
R.F., D.A. Miller and C.J. Nelson, eds. 1995. Forages volume 1: an introduction
to grassland agriculture, fifth edition. Iowa State University Press,
Ames, USA. Pp. 21, 401.
2. Gould, F.W. 1951. Grasses of the southwestern United States. The University of Arizona Press, Tucson, USA. P. 149.
3. Hitchcock, A. S. 1971. Manual of the grasses of the United States, A. Chase (rev.) Dover Publications, New York, USA. Pp. 828, 540, 532.
4. Mayes, V.O. and B. B. Lacy. 1989. Nanise, a Navajo herbal: one hundred plants from the Navajo reservation. Navajo Community College Press, Tsaile, USA. P. 45.
