Prosopis glandulosa Torr.

by Karen Howe, Native Plants Class 2003
Common names: Honey Mesquite, Western Honey Mesquite, Mesquite
Family: Fabaceae
Synonomy: None
Etymology: The genus Prosopis refers to the Greek name for burdock (a very different spiny plant). The species, glandulosa is Latin meaning “full of gland.” The common name is derived from the Aztec name for tree = mesquite (1,3).

Identification:
Growth form: Large tree or shrub up to 6 m tall and 30 cm in diameter. Can be single-stemmed (tree) or multi-stemmed (small tree/shrub) (4,5).
Roots: Roots extend both laterally and vertically. Taproot depth can reach as low as 190’ (5).
Stem: Stems are arched with stipular spines (2).
Leaves: Leaves are 2-4 bipinnately alternate with leaflets in pairs, opposite and many (1,2).
Inflorescence/flowers: A spikelike raceme 6-10 cm. Flowers are small, greenish-white to yellow, short-lobed, petals inconspicuous (1,2).
Fruit: A long, linear pod with thin, leathery pale yellow covering. There are many (8+) oblong seeds that are surrounded by a sweet pulp (1,2).
Similar species: Can be confused with Acacia greggii which has hairy stems, 2-3 leaflets and a dehiscent fruit compared to P. glandulosa having no hairy stems, generally 1 pair of leaflets and a fruit that is not dehiscent (3).

Ecology
Life history: Perennial shrub or small tree.
Native/introduced: Native to Southwest United States.
Photosynthetic pathway:
Phenology: Flowers from March to August with fruiting in July-August.
Distribution: Occurs on a variety of soil types and in grasslands, alkali flats, washes, mesas, alluvial flats, and valleys up to 5000’. Is found in Cononino, Cochise, Santa Cruz, Pima and Yuma Counties in Arizona. Occurs from California west to Kansas (1,3).

Uses
Mesquite has a variety of uses including food, medicine, tools and shelter. The pods of mesquite are sweet and eaten whole (pods were chewed and sucked when green and yellow). A juice is extracted from pounded pods and water and sometimes fermented. Flour was made using dry, ripened pods and processed into large cakes for preservation. Pieces broken off from the cake were added to stews or water was added to make a thin gruel. The flour was a basic staple for natives of the U.S. southwest. Candy was made from the clear sap exuded by the bark. A darker sap was used as a black dye. Most parts of the tree were also used medicinally including the leaves, bark, and roots for eye treatments and as a gastrointestinal aid. Wood is used for fire and posts (1,5,6)

References
1. Allen, O.N. and E.K. Allen. 1981. The Leguminosae. A Source Book of Characteristics, Uses, and Nodulation. The University of Wisconsin Press, Madison.

2. Athenic Systems: TreeGuide Species details. http://www.treeguide.com/Species.asp?Region=NorthAmerican&SpeciesID=783\

3. Baldwin, B.G., S. Boyd, B.J. Ertter, R.W Patterson, T.J. Rosatti, and D.H. Wilken. 2002. The Jepson Desert Manual. Vascular Plants of Southeastern California. University of California Press. Berkeley.

4. Benson, L. and R.A. Darrow. 1981. Trees and Shrubs of the Southwestern Deserts. University of Arizona Press. Tucson.

5. U.S. Forest Service, Fire Effects Information System. http://www.fs.fed.us/database/feis/plants/tree/progla/all.html

6. Moerman, D.E. 1998. Native American Ethnobotany. Timber Press. Portland, Oregon.