Fabaceae (Mimosoideae)

©The World Botanical Associates Web Page
Prepared by Richard W. Spjut
Dec 2007, Feb 2013

Prosopis glandulosa var. glandulosa
AZ: 20 mi NW of Wickenberg,
Sep 2007


Prosopis glandulosa var. torreyana
TX: El Paso Co., sand dunes.
Oct 2007


Prosopis glandulosa var. torreyana
CA: Kern Co., Tejon Ranch.
24 Mar 2012


Prosopis pubescens
Inyo  Co.
Base of Panamint Range,
Ballarat Road

SPJ-16,286, 08 May 2008



Prosopis velutina
AZ: Maricopa Co, between Why and Ajo, Oct 2007

Trees and Shrubs of Kern County (Jan 2013)

     Prosopis. Deciduous shrubs or trees with solitary or paired spines at base of spur-like shoots (P. glandulosa) or leaves (P. pubescens); leaves appearing in mid to late spring or summer, alternate, twice divided, initially the petioles dividing dichotomously into a pair of  pinnae, each pinna with an even number of numerous opposite leaflets (even pinnate) along the branch (rachis), or pinnately divided into several pairs of pinnae; flowers in cylindrical to spherical masses on one or more (fasciculate) axillary shoots, yellowish or cream, 5-merous, stamens twice the number of petals, exserted beyond petals; fruits long cylindrical, indehiscent, segmentally or spirally constricted between seeds. ± 44 species in subtropical woodlands and desert washes; 3 in California, 2 native, 1 native and 1 introduced in Kern County, possibly a third species known to occur near Fresno.

Key to Prosopis

1. Fruit shoots with fruits radiating in all directions; fruit coiled
like a snail shell; leaf pinnae with cupular glands at base........... Prosopis pubescens

1. Fruits dangling, straight to curved; fruit transversely segmented;
leaf pinnae without basal cupular glands.............. ................................................. 2


2. Leaflets 14–34, (1-) 1.5–2.5 cm............................................. Prosopis glandulosa

          2. Leaflets 30–60, 2.0–9.0 cm                                                .........  Prosopis velutina

Prosopis glandulosa Torrey 1827 var. torreyana [P. juliflora (Mimosa juliflora Swartz 1788) DeCandolle 1825 var. torreyana L. D. Benson 1941] M. C. Johnston 1962. Mesquite.
Spiny shrub or tree with crooked trunk; leaves twice divided, initially into one pair of pinnae and then into 14–34 leaflets, each leaflet usually 15–25 mm in length, hairless; flowers appearing Apr–Jun; yellowish in cylindrical catkin-like racemes; fruit persistent, 1-several dangling together, aging red, long-linear (5–15 (-20) cm), narrow, compressed to the shape of the seed chamber and constricted between seeds.  Widely distributed in the Southwest U.S. and into Mexico. Mesquite thicket recognized in MCV2 when >3% when dominant and >3% absolute cover. Type from Colorado River, eastern  San Bernardino Co., Needles. Kern Co.: “Common on hundreds of acres of alkali plains east and north-east of Buena Vista Lake; less common throughout the slough country north to Tulare Lake” with isolated occurrence along Poso Creek above Round Mountain, and occasional in the desert (Twisselmann), 64–304 m (CCH, none from the desert, which would be higher in elevation).  Grounded seeds used for making flour and beer; gum from bark used in preparing meat, the bark itself used to make baby diapers, or skirts, flowers a source of honey, fruits fed to cattle, leaves used in medicine for eyewash, for reducing fevers, and as an antiacid.

Prosopis pubescens Bentham. Screwbean. A native species distinguished by the coiled fruits. Known from the valley in Fresno Co, while generally found in the desert Southwest.  Kern Co.: CCH: 15 mi. North of Mojave on U.S. 6, 762 m, S. Albright, 21 Apr 1957, roadside, sandy soil (UCSB3465), possibly cultivated.

Prosopis velutina Wooton 1898. Velvet mesquite. Differs from the common mesquite in the smaller hairy leaflets, 4–15 mm long. A native to the southwestern deserts that is reported in JP2 to occur in the valley. Type from mesas and valleys, AZ. Kern Co.: Two records in CCH: (1) 1/4 mile north of Las Yeguas Ranch, Temblor Mountains, 2,500 ft (collected by Twisselmann, 11 Aug 1954), and (2) Hwy 223 and Old River Road, 4.0 mi south of Old River (collected by Steve Boyd, 21 Jul 1978). Not in Twisselmann or Moe.


Pharmaceutical References

Mazzuca M., W. Kraus and V. Balzaretti.  2003. Evaluation of the biological activities of crude extracts from patagonian prosopis seeds and some of their active principles. J. Herb. Pharmacother. 3(2): 31–37. “Extracts of different polarities from three species and three varieties of the genera Prosopis: P. alpataco, P. denudans var. denudans, P. denudans var. patagonica, and P. denudans var. stenocarpa, were screened in order to evaluate their antibacterial, antifungal, antifeedant, antihelminthic, molluscicidal and toxic activities. The extractions of the plant materials were carried out successively with petroleum ether, dichloromethane, ethyl acetate, methanol and water. All petroleum ether extracts showed antibacterial activity. The dichloromethane extract of P. alpataco showed antibacterial and antifungal activities. Methanol and aqueous extracts of P. denudans var. denudans and P. denudans var. patagonica showed antifungal activities and a slight response to the toxicity test. Fatty acids and a group of pentacyclic triterpenes were identified as responsible for antibacterial activities in some of the active extracts.