Mesquite Prosopis velutina Wooton; Prosopis pubescens Benth. Fabaceae Species description Mesquites are desert-adapted, winter and drought- deciduous, spiny shrubs or trees; they may have a single trunked or be multi-stemmed with a rounded crown of twisting branches. The tiny leaves are bipinnately compound. The bark is thick and rough, and on older branches and trunks generally turns dark brown. Most mesquite species have long, stout, sharp spines that often occur in pairs. The perfect, pale-yellow flowers bloom on spike-like racemes (like catkins) from mid- March through May in the southwestern U.S. The leguminous pods are long, fleshy, tan or mottled with several small, brown, hard seeds. Natural and cultural history Mesquite are native to the southwestern U.S. and northern Mexico; and depending on the species, may grow on hillsides, open plains, valleys and river bottoms, and along washes. Mesquite are long-lived, moderate-fast growing shrubs or small trees that can reach a height and canopy diameter of 30 feet. The species occurs primarily below 5,500 feet in elevation, and is frost tolerant to below 20ºF. Mesquite pods were a highly nutritious and critical food resource to Native Americans in the Southwest and northern Mexico. Planting considerations and propagation techniques Mesquite trees require full sun. Though highly adaptable, they grow best in deep floodplain soils found naturally near washes. The flowers are insect pollinated. If propagated by seed, they require mechanical scarification. The tree easily hybridizes, especially with non-native mesquites. For high-quality pods, mesquites are grown in isolated populations to ensure the desired characteristics. Water needs Mesquite trees have medium-low water requirements once established, depending on the species. Mesquite bosques, or forests grow in low valleys and along shallow washes where their deep taproots can reach the water table. Care The trees are spiny, depending on species and should be kept pruned to shape in public spaces. Harvesting and processing The mesquite pod pulp (surrounding seed) is edible. Harvest before the first rain of the summer, or long after the rainy season in the dry conditions of late summer and fall. Rain on mature or nearly mature pods can cause a common soil fungus to grow on mesquite pods. The season in southern Arizona typically begins in late June and stretches into October. Native trees are adapted to two rainy seasons (winter and summer), and typically go through two flowering phases, one in the spring (March-May) and the other after the monsoon (August). This results in two fruiting phases. Ripe pods may range in color from yellowish tan to reddish (not green), and are dry and brittle. They come off the tree with little pulling. Store in paper bags until processing. Pods will need to be milled with a hammermill, which can crush and grind both the pith and the seeds of mesquite pods and sift out most of the debris. Native mesquite pod flour is delicious in a wide array of cooking and baking. As a legume, it is gluten free and rich in soluble fiber. Mesquite flour is also higher in protein than most conventional grain flours. Follow specific baking recommendations to incorporate mesquite flour into baking recipes. References and resources Desert Harvesters: Appreciating the native foods of the Sonoran Desert, mesquite. http://www.desertharvesters.org/native-plant-food-guides-the-desert-can-feed-you/mesquite/ Hodgson, W.C. 2001. Prosopis – Mesquite. pp. 178-188. Food Plants of the Sonoran Desert. University of Arizona Press, Tucson, AZ. Martin, S.C., and R. R. Alexander. 1974. Prosopis juliflora (Swartz) DC. In Seeds of Woody Plants in the United States, edited by C. S. Schopmeyer. Agricultural Handbook #450. Forest Service, U.S. Department of Agriculture, Washington D.C. Spellenberg, R., C.J. Earle, and G. Nelson. 2014. Trees of Western North America. Princeton University Press, Princeton, NJ. Uchytil, R. J. 1990. Prosopis velutina. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). http://www.fs.fed.us/database/feis/ [2015, June 17]. 2 .