Robinia neomexicana

Taxonomy: Leguminosae or Fabaceae Family

Subfamily: Papilionoideae

Common Names: Locust, Mexican Locust, New Mexican Locust, New Mexican Robinia, New Mexico Locust, Southwestern Locust, Thorny Locust, and Western Locust

By: Alberta Hayes, Michelle Brown, Raymond Sells (Summer 2001)



    Robinia neomexicana is a member of the Pea Family (Leguminosae or Fabaceae), and is native to the southwestern and southeastern parts of the United States. New Mexico locust is found from the western mountains of Trans-Pecos Texas, Arizona and New Mexico, north to southern Colorado and to the dry hills and stream banks in southern Nevada. It is encountered in dense thickets at elevation from 4000 to 8500 feet in the southwestern United States.  It appears equally on basalt and limestone soils and appears to tolerate alkali clay soils. These trees favor canyons or slopes from the upper pinon-juniper zone up into the ponderosa pone and mixed conifer eco-zones (Dunmirne 121).

photograph by: Raymond Sells



    New Mexico locust is a rare spiny shrub or small tree and forms large thorny thickets that sprout freely from stumps and roots. The locust trees can reach the height of 15 feet or more with purplish-pink fragrant flowers and numerous leaflets.  Bark of trunk light brown, thin and slightly furrowed, the ridges with small plate-like scales (Peattie 591). Branches have stipular spines. Leaves are grayish with 9 to 15 elliptic to elliptic-lancelet leaflets, 0.25 to 1.25 inches long. Flowers are reported to range from white, pale pink, rose, purplish pink, to deep red. Flowers are about 0.5 inches long in dense, many flowered racemes. The flowers open in May or June in dense, racemes and sometimes nearly white. The flower are hermaphrodite (have both male and female organs) [1]. Fruit seed pods are 2 to 4 inches long, 1/3 inch wide with a narrow wing (Peattie 591). Seeds 1/16 inch long, dark brown and slightly mottled (Peattie 591). The wood is very hard, strong, heavy (50 pound per cubic foot), the heart wood yellow streak with brown, the sap wood lighter yellow and thin (Peattie 591). The twigs are covered with glandular hairs which persists for at least one season, after which they became reddish brown and often glorious (Peattie 591). 




1. New Mexico locust seed is pre-soaked in warm water for 48 hours that are later sown individually in pots during their first winter, plant lets are planted outdoors during the summer months. [1] The seed is usually dispersed August-December and should be collected before the pods open by stripping the pods and beating them in a bag. The seed is then spread out to dry, and the debris removed by fanning. About 20 lbs of seed is yielded from 100 lbs of fruit.  

2. Commercial seed has a accuracy of 96 percent and a purity of 98 percent. If stored in a cool dry place they retain viability 1-4 years. For pretreatment he seed may be soaked in hot water at 212 degrees Fahrenheit or less 1-5 minutes, followed by soaking in water a room temperatures for 10 hours (Vines 567). During the spring the seed is planted a foot apart and no mulch or shade is required .



Medicinal Uses:

   Robinia neomexicana has some medicinal application. For example, the Hopi Indians have used it as an emetic (to induce vomiting) and for treating rheumatism (arthritis). The bark, roots, and seed are said to be poisonous.  


Apache (Chiricahua, Mescalero, White Mountain)
  • seed pods are eaten fresh
  • seed pods are cooked and stored for winter usage
  • flowers boiled, dried, and stored for winter usage
  • fresh flowers cooked with meat or bones for flavoring (Mescalero)
  • bean and seed pods are used for food (White Mountain)
  • large clusters of flowers eaten without preparation and used as an early summer for their diet.


Apache (Chiricahua, Mescalero, White Mountain)
  • wood is used to make hunting and fishing equipment
  • wood is used to make hunting and fishing equipment


  • wood is used to make bows
Other Uses:
  • branches are used to make cradleboards and wood are cured for a year to make hunting bows (Hualapai Fiber)
  • branches are used to make hunting arrow shafts (Keres)
  • soil stabilization (wood)
  • wood are used for fence posts

Chemical Structure


Introductory ., 06/08/01, Introductory 

Horticopia Plant Information ., 07/11/01, Robinia neomexicana 

New Mexico Locust . MexicoLocust.htm . 06/08/01, New Mexico Locust 

Robinia neomexicana . wysiwyg://38/http://www.comp.leeds...tml?Robinia+neomexicana&CAN=LITIND, 07/11/01, Robinia
neomexicana . 

Robinia--Locust Tree., 07/11/01, Kings American Dispensatory: Robinia.

Arnberger. Leslie P. Flowers of the Southwest Mountain. Tucson, AZ: Southwest & Parksand Monument. p. 121.

Kearney, Thomas H. and Robert H. Peebles. Arizona Flora. Berkeley, CA: University of California Press. P. 441-42.

Result of Research. 7/23/01. Search for Robinia neomexicana found 14 matches.

Technology transfer. 7/11/01, Robinia neomexicana.

Robinia neomexicana A. Gray. 7/11/01, Robinia neomexicana.

New Mexico Locust, Southwestern Locust, Hojalito. 7/1/01, Texas Native Plants

Dunmirne, William W. and Gail D. Tierney. Wild Plants of the Pueblo Province. Santa Fe, NM. Museum of New Mexico Press, 1995, p. 66, 120-21.

Britton, Nathaniel L. and John Adolph Shafer. North Americans Trees. New York: Henry Holt and Company. P. 556-57.

Peattie, Donald Culross. A National History of Western Trees. Lincoln: University of Nebraska Press. 1908. p. 591-92.

Vines, Robert A. Trees, Shrubs and Woody Vines of the Southwest. Austin, TX: University of Texas Press. 1960. p. 567.