Carnegiea gigantea, Giant Saguaro

Southwest Desert Flora

Home to the plants of the Sonoran, Chihuahuan and Mojave Deserts

Cirsium ochrocentrum, Yellowspine Thistle

Parkinsonia aculeata, Jerusalem Thorn

Jerusalem Thorn has 1 inch (2.5 cm), showy bright yellow flowers that fad to orange. The trees may be distinguished from other Palo Verde trees by its red or red banner flower banner petal as shown in the photo. Parkinsonia aculeata Jerusalem Thorn is a small tree or shrub that is grows in elevations ranging from 2,000 to 4,500 feet (610 - 1,372 m). Parkinsonia aculeata Jerusalem Thorn, also called Mexican Palo Verde, is a beautiful tree with bright green or yellow green branches, trees have smooth green bark that is able to photosynthesize. Parkinsonia aculeata Jerusalem Thorn usually flowers in March and May with minor flowering throughout the year particularly following monsoon rainfall. As shown in the photo the tree has spines, typical of desert dwelling trees. Parkinsonia aculeata Jerusalem Thorn thrives in warm border state in North America and Mexico. Plants are fast-growing and the new growth is lush and attractive. Parkinsonia aculeata

Scientific Name: Parkinsonia aculeata
Common Name: Jerusalem Thorn

Also Called: Horse Bean, Horsebean, Jerusalem-thorn, Mexican Palo Verde, Paloverde, Retama (Spanish: Guacaporo, Retama, Bagote,Lluvia De Oro, Huacapori, Junco Marino, Palo ver, Cacaporo, Guacóporo, Huacóporo, Espinillo, Mezquite Verde)

Family: Fabaceae or Leguminosae Family

Synonyms: ()

Status: Native

Duration: Perennial

Size: Up to 39 feet (12 m) and almost as wide, much smaller in habitat.

Growth Form: Jerusalem Thorn is a relatively small tree or multi trunk shrub; plants have spines as common with many desert dwelling trees; the branches are bright green or yellow-green and the smooth green bark is capable of photosynthesizing its own energy.

Leaves: Jerusalem Thorn trees have green leaves arranged alternately along the green stems; the leaves are pinnately compound; the small leaflets are in 1 to 3 pairs.

Flower Color: Jerusalem Thorn trees have bright yellow flowers that quickly fad to orange; the flowers are showy 1 inch (2.5 cm) wide with 5-petals; the bottom banner or standard petal may be diagnostic with its red or with red splotches; the fruit is a legume that splits open (dehiscent).

Flowering Season: March and May; with minor flowering throughout the year particularly following monsoon rainfall; April to October in California.

Elevation: 2,000 to 4,500 feet (610 - 1,372 m) throughout its' entire range; below 2,625 feet (800 m) in California.

Habitat Preferences: Commonly found in arroyos and low desert areas where water regularly drains; in certain other areas there may be found in sandy soils along washes; they are often found in limestone soils in Texas.

Recorded Range: In the United States Jerusalem Thorn is found primarily in the border states in AL, AZ, CA, FL, GA, HI, LA, MS, NM, NV, SC, TX and UT. It is also native to Baja California, Mexico and northern South America. In Arizona, Jerusalem Thorn is found in central and southern Arizona.

North America & US County Distribution Map for Parkinsonia aculeata.

North America species range map for Parkinsonia aculeata:

North America species range map for Parkinsonia aculeata:
Click image for full size map.

Invasive/Noxious Weed Information: Unknown
Threatened/Endangered Information:Unknown

U.S. Wetland Indicator: In North America Parkinsonia aculeata has the following wetland designations:
  • Arid West, FAC
  • Atlantic and Gulf Coastal Plain, FAC;
  • Caribbean, FAC;
  • Great Plains, FAC;
  • Hawaii, FACU;
  • Western Mountains, Valleys, and Coast, FAC;

  • FAC = Facultative, occur in wetlands and non-wetlands
    FACU = Facultative Upland, usually occur in non-wetlands, but may occur in wetlands. U.S. Weed Information: Unknown

    International Invasive/Noxious Weed Information: 1The Centre for Agriculture and Bioscience International, (CABI), and 2The Invasive Species Compendium (ISC) has identified Parkinsonia aculeata as an “Invasive Species, Pest and Host Plant”.

    This is one of the most widespread and well-known woody weeds in hot regions, and has become naturalized and shown weedy tendencies in all countries where it exists, whether native or introduced. It is disliked for its thorns, forming dense impenetrable thickets that degrade pasture, choke waterways and prevent cattle reaching water. It was often introduced as a fodder, hedging or ornamental tree, with an ability to tolerate the driest and most saline sites and water logging, but prolific seeding led to rapid spread. It is a prohibited weed in Australia and a serious pest in parts of other countries such as tropical Africa, Hawaii, and other Islands in the Pacific Ocean.

    1The Centre for Agriculture and Bioscience International (CABI), Wallingford, Oxfordshire, England; The US Department of Agriculture is a lead partner with CABI.

    2The Invasive Species Compendium (ISC) is an encyclopedic resource that brings together a wide range of different types of science-based information to support decision-making in invasive species management worldwide.

    Genus Information: In North America, USDA Plants Database lists 4 species and 6 accepted taxa overall for Parkinsonia. Worldwide, World Flora Online includes 13 accepted species names for Parkinsonia.

    The genus Parkinsonia was published in 1752 by Carl Linnaeus, (1707-1778).

    In the Southwestern United States: Arizona, California and Texas each have 3 species of Parkinsonia, Nevada has 2 species and New Mexico and Utah each have 1 species. Data approximate, subject to revision.

    Comments: Jerusalem Thorn is a widely cultivated species in warmer areas. Occurrence of this species as “native” in central Arizona is likely more of an escapee from cultivation as opposed to a true native. It is easy to grow as its seeds are quick to sprout without additional preparation. This species thrives in poor alkaline soil. New lush growth is much more attractive than old growth.

    Key distinguishing features that are generally, not always accurate separating 3 similar species of local Paloverde trees is the color of the large banner or standard petal as follows;

  • Jerusalem Thorn has a red, brown or a few red splashes on the banner petal.
  • Yellow Paloverde has a white banner petal.
  • Blue Paloverde has a yellow banner petal.
  • Importance to Wildlife, Birds and Livestock
    Parkinsonia aculeata has 1 inch (2.5 cm) attractive flowers, the flowers, their seeds and plants may be visited by hummingbirds and/or small mammals including rodents and granivorous birds in search of food, nectar and protection through cover. Livestock and wildlife may forage on the leaves and seed pods during drought times when there is little else to feed on.

    Beneficial Value to Butterflies, Honey Bees and Insects
    Parkinsonia aculeata has attractive flowers, the flowers and their plants may be visited or used by butterflies, moths, flies, honeybees, native bees and other insects in search of nectar, food or shelter and protection.

    The genus “Parkinsonia” is named in honor of the English botanist John Parkinson (1567–1650). The genus Parkinsonia was published in 1752 by Carl Linnaeus, (1707-1778).

    The species epithet aculeata means prickly.

    The species epithet Jerusalem Thorn is from the Spanish and Portuguese word “girasol” which translated means “turning toward the sun”.

    Ethnobotany - Native American Ethnobotany; University of Michigan - Dearborn
    Parkinsonia aculeata is used for a multitude of purposes by southwestern United States indigenous peoples.
  • Papago Food, Dried Food; Beans flailed, winnowed, parched and used for food.
  • Papago Food, Dried Food; Seeds basket winnowed, parched, sun dried, cooked, stored and used for food.
  • Papago Food, Unspecified; Seeds used for food.

  • See complete listing of ethno-botanical uses at Native American Ethnobotany, University of Michigan, Dearborn.

    Date Profile Completed: 09/03/2015, updated 12/02/2021
    References and additional information:
    Arizona Flora, Kearney, Thomas H., Peebles, Robert H., 1960, University of California Press, Berkley and Los Angeles, California.
    U.S. Dept. of Agriculture, Natural Resources Conservation Service on-line database and USGS ITIS search - (accessed 11/26/2021)
    World Flora Online; A Project of the World Flora Online Consortium; An Online Flora of All Known Plants - (accessed 11/26/2021)
    Native Plant Information Network, NPIN (2013). Published on the Internet [accessed: 11/26/2021]. Lady Bird Johnson Wildflower Center at The University of Texas, Austin, TX.
    Wiggins 1964, Benson and Darrow 1981, Kearney and Peebles 1969 from SEINet online, accessed 11/26/2021.
    Martin F. Wojciechowski 2012, Parkinsonia aculeata, in Jepson Flora Project (eds.) Jepson eFlora, (accessed 11/26/2021).
    CABI, 2021 Mexican Paloverde, Parkinsonia aculeata. In: Invasive Species Compendium. Wallingford, UK: CAB International. (accessed 11/26/2021).
    SEINet for synonyms, scientific names, recorded geographic locations and general information
    Etymology:Michael L. Charters California Plant Names: Latin and Greek Meanings and Derivations; A Dictionary of Botanical and Biographical Etymology - (accessed 11/26/2021)