Common Name: Jerusalem Thorn

General Information

Parkinsonia aculeata is a small evergreen spiny tree with an open, spreading, globose crown; it can grow 4 - 10 metres tall. The bole is often crooked and branching from low down, it can be up to 40cm in diameter[, ].
The tree is sometimes harvested from the wild for local use of its edible seed. It is able to grow in very harsh conditions, including seasonal flooding, and so is often used in difficult situations in soil stabilization and afforestation projects[]. It is also used as a hedge, and is often grown as an ornamental, where it is valued especially for its abundant and long-lasting floral display[].
The seeding of this tree is prolific and it reproduces so easily that it can escape from controlled cultivation and become a weed[]. It forms impenetrable thorny thickets that compete with and exclude native species[]. It is considered to be invasive in parts of the Mediterranean, the southern USA and many parts of Australia[]

Known Hazards

The leaves are reported to contain hydrocyanic acid and to be toxic[].

Botanical References

Range

S. America - Argentina, Uruguay, Paraguay, Brazil, Bolivia, Peru, Ecuador; C. America - Panama, north to the southern USA

Habitat

Semi-desert vegetation, mainly in desert valleys and desert grassland zones, at elevations up to 1,300 metres in the subtropics and up to 2,400 metres in the tropics[].

Properties

Weed Potential	Yes
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Evergreen Tree
Height	7.50 m
Growth Rate	Fast
Pollinators	Bees
Cultivation Status	Cultivated, Ornamental, Wild

Cultivation Details

A plant of the semi-arid tropics and subtropics, where it is found at elevations up to 2,400 metres in the tropics; it has also spread as a weed into some warm temperate regions. It grows best in areas where annual daytime temperatures are within the range 24 - 32°c, but can tolerate 16 - 36°c[]. When dormant, the plant can survive temperatures down to about -4°c, but young growth can be severely damaged at -1°c[]. It prefers a mean annual rainfall in the range 300 - 700mm, but tolerates 200 - 1,000mm[].
Requires a sunny position[, , ]. Succeeds in well-drained, sandy to loamy soils[]. Tolerant of a wide range of soils, including poor, gravely or sandy soils[, ]. Plants can tolerate moderate levels of salt in the soil[]. Prefers a pH in the range 6.5 - 7.5, tolerating 6 - 8.5[]. Tolerates very acid soils[]. Plants can withstand droughts of up to 9 months, and also seasonal waterlogging of the soil[, ].
The tree is fast-growing but short-lived[]. It can reach a height of 2.5 metres within 2 years from seed[]. Young fertilized plants can grow up to 1 metre annually[].
Plants respond well to coppicing and trimming[].
The branches of wild plants are often hollow and inhabited by ants[].
There are conflicting reports on whether or not this tree has a symbiotic relationship with certain soil bacteria, so it is unclear as to whether this tree fixes atmospheric nitrogen[].

Edible Uses

Seed - raw or cooked[, , , ]. The mature seed is dried, then cooked when required[].
The seeds are rich in protein (they contain around 21% protein, 62% carbohydrate and 8% fat) and have potential for use as a human food[]. The dried, powdered seed has a digestibility rating of 76%, increasing to 85% when cooked - this is higher than for many of the commonly eaten legume foods. The seeds do contain antinutritional factors, including trypsin inhibitors, phenols, alkaloids and haemagglutinin, but these are not present in high enough concentration to constitute a major nutritional problem. These antinutritional factors are soluble in saline solutions and can be removed by soaking or during cooking[].

Fruit - raw[]. The pulp inside the seedpodhas a sweet flavour, containing up to 60% sugars[].

Medicinal

Leaf, fruit and stem decoctions are taken orally and applied externally to treat fever, atony and malaria[, ]. The decoction is also said to be abortifacient[].

Flower and leaf extractions in alcohol are applied as a poultice to treat rheumatism[].

Agroforestry Uses:

The tree is used for erosion control and reforestation in sandy, arid areas[, ].
It is a useful plant for the reclamation of wastelands, gullied areas and mining spoil[]. It provides a large amount of leaf litter that can be applied as a mulch to the soil[].
The plant forms impenetrable hedges and makes an effective windbreak[, ].

Other Uses

The heartwood is light brown; it is clearly demarcated from the thick band of yellowish sapwood[, ]. The wood is close-grained, moderately heavy, hard, very compact and of high durability. Where available in sufficient size it is used for general carpentry, otherwise it is used for light poles and posts[303. 331, ].
The wood burns well and makes a good fuel, it is also used to make charcoal[, , ].

Propagation

Seed - some of the seed has a hard seedcoat and benefits from scarification before sowing to speed up germination. This can usually be done by pouring a small amount of nearly boiling water on the seeds (being careful not to cook them!) and then soaking them for 12 - 24 hours in warm water. By this time they should have imbibed moisture and swollen - if they have not, then carefully make a nick in the seedcoat (being careful not to damage the embryo) and soak for a further 12 hours before sowing. Sow the seed in a sunny position in a nursery seedbed or in individual containers. A high germination rate can be expected, with the seed sprouting within 8 - 16 days[]. The plants should be ready to plant out 8 - 10 months later[].
Root cuttings[].
Layering[].