Bouteloua eriopoda (Torr.) Torr.

by Amanda M. Kuenzi, Native Plants Class 2003
Common names: Black grama, woollyfoot grama, hairy foot grama. (7)
Family: Poaceae (8)
Synonymy: Chondrosum eriopodum Torr. (8)
Etymology: The genus refers to two Spanish brothers, Claudio and Esteban Boutelou, both botanists who lived in the late 1700’s to early 1800’s. (4) The specific epithet, ‘eriopoda,’ translates to “woolly foot” or “woolly stalk.” (2)

Identification
Growth form: A perennial herb that reaches 2 feet in height.(8)
Roots: Black grama has a well developed, finely divided root system that is mostly concentrated in the upper 10 inches of the soil, but may reach up to 4 feet deep in sand. Periodic rainfall is exploited by rapid root growth and water absorption. (7)
Stem: Wiry, spreading stems grow 8-24 inches in height, woolly-pubescent on the lower internodes. (3,7) Hard and knotty at the base. Upper sheaths shorter than internodes (6)
Leaves: Blades are smooth, narrow, wavy, pointed, inrolled, grayish-green, mostly basal, 1-5 inches long and 0.5-2 mm wide. (3,7,5)
Inflorescence/flowers: Inflorescence a panicle, with 3-8 spikelets on each unilateral branch. Spikelets are comb-like, with long awns, mostly infertile, growing only on one side of the branch. Glumes 6-9 mm long. (3,7)
Fruit: Low production of viable seed because reproduction is mainly by runners. The spikelets persist on the stalk. (5)
Similar species: Bouteloua eriopoda is distinguishable from Bouteloua gracilis in that B. eriopoda has more spicate branches and the heads are straighter. B. gracilis does not have hairy internodes on the stalk.

Ecology
Life history: Perennial grass which primarily reproduces by runners. (8, 5)
Native/introduced: Native (8)
Photosynthetic pathway: C4 (1)
Phenology: The active growth period is spring and fall.(8) Blooming occurs during late summer and fall rains. (7)
Distribution: Widely distributed throughout southwestern desert grasslands and rangelands; it is a principle native dominant on upland sandy, loamy soils. Found on dry, sandy mesas and rocky slopes between 3,500 and 6,000 feet, black grama grows in Mexico, Arizona, California, Colorado, Kansas, Nevada, New Mexico, Oklahoma, Texas, Utah, and Wyoming. (3,7,8)

Uses
A highly palatable, highly nutritious forage grass for all classes of livestock and wildlife year long. (7,8) It is also a minor component of the nests of Cactus wrens in the southern Chihuahuan Desert of New Mexico and Arizona. (7)

References
1. Gibbens, R.P., Ralph A. Hicks and William A. Dugas. 1996. Structure and function of C3 and C4 Chihuahuan Desert plant communities. Standing crop and leaf area index. Journal of Arid Environments 34:47-62.

2. Gledhill, D. 1985. The Names of Plants. Cambridge University Press, New York.

3. Gould, F.W. 1993. Grasses of the Southwestern United States. University of Arizona Press, Tuscon.

4. Hyam, R. and R. Pankhurst. 1995. Plants and their Names, A Concise Dictionary. Oxford University Press, New York.

5. Ruyle, G.B. and D.J. Young. 1997. Arizona Range Grass. University of Arizona. Tucson, Arizona, USA.

6. Shreve, Forrest and Ira L.Wiggins. 1964 Vegetation and Flora of the Sonoran Desert, volume 1. Stanford University Press, Stanford, California, USA.

7. Simonin, Kevin A. (2000, August). Bouteloua eriopoda In: USDA, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (2003, October). Fire Effects Information System, [Online]. Available: http://www.fs.fed.us/database/feis.

8. USDA, Natural Resource Conservation Service Plants Profile. 2002, The PLANTS Database, Version 3.5 (http://plants.usda.gov). National Plant Database Center, Baton Rouge, LA 70874-4490 USA.