Agroforestree Database

Local names:
 Arabic (mesquite), English (western honey mesquite,mesquite,honey mesquite), Spanish (algoroba)

Prosopis glandulosa is a tall shrub or tree of 3-9 m; deciduous foliage; spines axillary, uninodal, 1-4.5 cm long, mostly solitary, sometimes very few, germinate alternately on different nodes of the same twig. It is a plant with a very deep root system (up to 18.3 m).

Leaves glabrous, uni- or bijugate; petiole (with rachis when extant) 2-15 cm long; pinnae 6-17 cm long; leaflets 6-17 pairs, about 7-18 mm distant on the rachis, linear or oblong, obtuse, glabrous, subcoriaceous, prominently veined underside; costa frequently of lighter colour, (min. 1.5) 2-6.3 cm long x 1.5-4.5 mm broad, 5-15 times as long as broad.

Racemes spiciform, about 5-14 cm long, multiflorous; petals 2.5-3.5 mm long; ovary stipilate, villous.

Legume straight, 8-30 cm x 5-13 mm, rarely subfalcate, compressed to subterete, submoniliform, glabrous, straw-yellow or tinged with violet, short-stiped, with strong, short, or elongate acumen, 5-18 seeded; joints subquadrate to oval; seeds oblique to longitudinal.

There are 2 recognized varieties -:  P. glandulosa var. torreyana (Benson) Johnston grows primarily in the deserts and drylands of southwestern USA and northern Mexico; P. glandulosa var. glandulosa is found from Mexico north to Kansas and east to Louisiana. In North America the common name ‘mesquite’ (meaning charcoal tree) is used for several Prosopis species, whereas in South America the name ‘algarrobo’ is used commonly. Algarobbo is actually the Old World name for carob (Ceratonia siliqua); the conquistadores applied it to Prosopis species because of its carob-like appearance.

Ecology

Moderately salt and frost tolerant. It thrives under high temperatures and survives in areas with very low precipitation but is usually found in areas with groundwater reserves. In its drier, western range, it occurs along streams and in low-lying areas. In areas with more rainfall, it occurs on open range or in chaparral. 

It is known as a phreatophyte, a plant with a very deep root system (up to 18.3 m) that can extract moisture from the water table. It often grows in dense thickets near desert washes but also occurs at the base of sand dunes and other areas where the water table is close to the surface. 

It is already considered a nuisance, competing with grass for water and reducing the livestock-carrying capacity of 30 million hectares of rangeland in southwestern USA.

Native range
United States of America

Tree management

Although P. glandulosa is very drought tolerant, best growth is achieved in areas where the root system can reach the groundwater. In areas with low rainfall, especially in fast-draining soils, irrigation may be required during establishment. The tree coppices well. Annual production of wood on dry, low-quality sites may be less than 1 t/ha, but with sufficient water (even though slightly saline) trees can grow rapidly and yield over 5 t/ha/yr. Fencing or seedling protectors will usually be needed to protect young transplanted P. glandulosa seedlings from rabbits or other browsing and grazing animals.

Seed storage behaviour is orthodox; no loss in viability after 3 years of storage at -15 deg. C. There are about 30 000 seeds/kg.

Moderately salt and frost tolerant. It thrives under high temperatures and survives in areas with very low precipitation but is usually found in areas with groundwater reserves. In its drier, western range, it occurs along streams and in low-lying areas. In areas with more rainfall, it occurs on open range or in chaparral. 

It is known as a phreatophyte, a plant with a very deep root system (up to 18.3 m) that can extract moisture from the water table. It often grows in dense thickets near desert washes but also occurs at the base of sand dunes and other areas where the water table is close to the surface. 

It is already considered a nuisance, competing with grass for water and reducing the livestock-carrying capacity of 30 million hectares of rangeland in southwestern USA.

Pods ripen simultaneously and are easy to collect and store. They should be picked when the seed rattles in the pod, and stored in a dry place. The seeds have a very tough coating that must be scarified for germination by chipping, cutting, acid treatment or exposure to boiling water. Acid, however, may damage the seed if cuts are made in the seed during mechanical cleaning. Seeds germinate best at temperatures of 20-40 deg. C. and can germinate with 6 hours of wetting at 34 deg. C. Scarified or sprouted seed should be planted in a well-drained soil mix. If small containers are used, seedlings should be transplanted 2-3 weeks after germination to avoid disturbing the dominant taproot. Young seedlings can have root-to-shoot ratios as high as 10:1. Larger transplants can be grown in deep containers (7.5 cm wide by 100 cm deep) or in plant bands (4 cm x 40 cm). Propagation by cuttings, tissue culture and air-layering is possible.

Erosion control:  A stabilizer of shifting desert sands. 

  P. glandulosa pods were a primary food of the residents of the deserts of southwestern USA. Pods are quite sweet; the whole-pod composition is 80% carbohydrate, 13% protein, 25% fibre, and 3% fat. Unlike most beans, the pods are edible without cooking. They are still used as a food and beverage in Mexico. Pods could prove useful for production of flour, wine, tempeh and tofu products. Gum from the bark is edible.

Grinding improves the use of P. glandulosa pods for fodder. Sheep, goats and pigs are able to use a higher percentage of them in their diet than are cattle and horses. Cattle browse leaves of mature trees only on deteriorated rangeland.

Apiculture:  Bees favour the flowers, and P. glandulosa is highly valued for its flavour. The honey is light, of good quality and granulates quickly.

Wood, chips and charcoal are excellent fuels, and the wood smoke lends a pleasant flavour to cooked foods.

Timber:  P. glandulosa wood is very dense with a specific gravity of 0.7 or more, and its shirinkage on drying is very balanced. These properties make it excellent for woodworking.

Shade or shelter:  The shrub could be multibranched and act as a suitable windbreak.

Tannin or dyestuff:  The gum has for long been used as a source of dye.

Medicine:  P. glandulosa has been used for a variety of medicinal purposes, including lice control and treatment of sore throat, skin sores and ulcers. Reported to be a collyrium, emetic and laxative, P. glandulosa is a folk remedy for dyspepsia, eruptions, hernias and skin and umbilical ailments.

Gum or resin:  Produces quality gums that may have an economic value. Gum from the bark is used for glue in the tree’s native range.

Nitrogen fixing:  P. glandulosa forms symbioses with Rhizobia and Vasicular arbuscular mycorrhizae (VAM). There are active root nodules going many metres deep into the soil. The tree, with 30% canopy cover, can fix 30-40 kg atmospheric N/ha. 

P. glandulosa is also used for fencing.

Soil improver:  A provider of humus to the soil. 

Intercropping:  Deeply rooted, open canopied trees may provide little competition to field crops. May be established for alley cropping.