''Parkinsonia aculeata'' is a species of

perennial In horticulture, the term perennial ('' per-'' + '' -ennial'', "through the year") is used to differentiate a plant from shorter-lived annuals and biennials. It has thus been defined as a plant that lives more than 2 years. The term is also ...

flowering

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, e.g., including only woody plants with secondary growth, only ...

in the pea family,

Fabaceae Fabaceae () or Leguminosae,International Code of Nomen ...

. Common names include palo verde, Mexican palo verde, Parkinsonia, Jerusalem thorn, jelly bean tree, palo de rayo, and retama.

Etymology

The genus name ''Parkinsonia'' honors the English botanist John Parkinson (1567–1650), while the species Latin name ''aculeata'' refers to the thorny stem of this plant. The name "Jerusalem thorn" stems from a mistranslation of the Spanish/Portuguese word ''girasol'' ('turning toward the sun').

Description

''Parkinsonia aculeata'' may be a spiny shrub or a small tree. It grows high, with a maximum height of . Palo verde may have single or multiple stems and many branches with pendulous leaves. The

leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

and stems are hairless. The leaves are alternate and pennate (15 to 20 cm long). The flattened petiole is edged by two rows of 25–30 tiny oval leaflets; the leaflets are soon

deciduous In the fields of horticulture and botany, the term deciduous () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed Leaf, leaves, usually in the autumn; to the shedding of petals, aft ...

in dry weather (and during the winter in some areas) leaving the green petioles and branches to photosynthesize. The branches grow double or triple sharp spines long at the axils of the leaves. The

flower Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...

s are yellow- orange and fragrant, in diameter, growing from a long slender stalk in groups of eight to ten. They have five sepals and five petals, four of them clearer and rhomboid ovate, the fifth elongated, with a warmer yellow and purple spots at the base. The flowering period is in the middle months of spring (March–April or September–October). The flowers are pollinated by bees. The

fruit In botany, a fruit is the seed-bearing structure in flowering plants (angiosperms) that is formed from the ovary after flowering. Fruits are the means by which angiosperms disseminate their seeds. Edible fruits in particular have long propaga ...

is a seedpod, leathery in appearance, light brown when mature.

Invasive problems

''P. aculeata'' is a major

invasive species An invasive species is an introduced species that harms its new environment. Invasive species adversely affect habitats and bioregions, causing ecological, environmental, and/or economic damage. The term can also be used for native spec ...

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

, as it is listed as a Weed of National Significance and is ranked as Australia's worst weed. It is also a major problem in parts of tropical

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

Hawaii Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only sta ...

, and other

Islands This is a list of the lists of islands in the world grouped by country, by continent, by body of water, and by other classifications. For rank-order lists, see the #Other lists of islands, other lists of islands below. Lists of islands by count ...

in the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...

. It was introduced to Australia as an

ornamental tree Ornamental plants or ''garden plants'' are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars th ...

and for shade around 1900. It is now a serious

weed A weed is a plant considered undesirable in a particular situation, growing where it conflicts with human preferences, needs, or goals.Harlan, J. R., & deWet, J. M. (1965). Some thoughts about weeds. ''Economic botany'', ''19''(1), 16-24. Pla ...

widespread through

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

, the

Northern Territory The Northern Territory (abbreviated as NT; known formally as the Northern Territory of Australia and informally as the Territory) is an states and territories of Australia, Australian internal territory in the central and central-northern regi ...

and

Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...

, covering about of land, and has the potential to spread through most of the

semi-arid A semi-arid climate, semi-desert climate, or steppe climate is a aridity, dry climate sub-type. It is located on regions that receive precipitation below Evapotranspiration#Potential evapotranspiration, potential evapotranspiration, but not as l ...

to subhumid tropical area in Australia. It forms dense thickets, preventing access for humans, native animals and

livestock Livestock are the Domestication, domesticated animals that are raised in an Agriculture, agricultural setting to provide labour and produce diversified products for consumption such as meat, Egg as food, eggs, milk, fur, leather, and wool. The t ...

to waterways. The fruits (seedpods) float, and the plant spreads by dropping pods into water, or pods are washed downstream by seasonal

flood A flood is an overflow of water (list of non-water floods, or rarely other fluids) that submerges land that is usually dry. In the sense of "flowing water", the word may also be applied to the inflow of the tide. Floods are of significant con ...

ing. Without the scarifying received by tumbling in streambeds, the seeds are slow to germinate. Several control methods are used to reduce the existing population and the spread of ''P. aculeata'' in Australia. Three

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

s have been introduced to Australia for

biological control Biological control or biocontrol is a method of controlling pests, whether pest animals such as insects and mites, weeds, or pathogens affecting animals or plants by using other organisms. It relies on predation, parasitism, herbivory, or o ...

; the parkinsonia bean weevils, ''Penthobruchus germaini'' and ''Mimosestes ulkei'', both have

larva A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

e that specifically eat the seeds from parkinsonia pods and are proving to be a useful management tool, and the parkinsonia leaf bug, ''Rhinacloa callicrates'', which destroys

photosynthetic Photosynthesis ( ) is a Biological system, system of biological processes by which Photoautotrophism, photosynthetic organisms, such as most plants, algae, and cyanobacteria, convert light energy, typically from sunlight, into the chemical ener ...

tissues but has had little overall impact on the plant. Fire is effective for young trees; mechanical removal and

herbicide Herbicides (, ), also commonly known as weed killers, are substances used to control undesired plants, also known as weeds.EPA. February 201Pesticides Industry. Sales and Usage 2006 and 2007: Market Estimates. Summary in press releasMain page f ...

s are also used.

Distribution

''P. aculeata'' is native to the

southwestern United States The Southwestern United States, also known as the American Southwest or simply the Southwest, is a geographic and cultural list of regions of the United States, region of the United States that includes Arizona and New Mexico, along with adjacen ...

and northern

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

south to Galapagos Islands and northern

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

. It has been introduced in

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

Pakistan Pakistan, officially the Islamic Republic of Pakistan, is a country in South Asia. It is the List of countries and dependencies by population, fifth-most populous country, with a population of over 241.5 million, having the Islam by country# ...

and

Spain Spain, or the Kingdom of Spain, is a country in Southern Europe, Southern and Western Europe with territories in North Africa. Featuring the Punta de Tarifa, southernmost point of continental Europe, it is the largest country in Southern Eur ...

Habitat

''Parkinsonia aculeata'' has a high tolerance to drought, simply attaining shorter stature. In moist and humus-rich environments it becomes a taller, spreading shade tree. This plant prefers a full sun exposure, but can grow on a wide range of dry soils (sand dunes, clay, alkaline and chalky soils, etc.), at an altitude of above sea level.

Uses

In Mexico, the leaves are steeped and made into medicine for fever and epilepsy. The foliage is seldom browsed by livestock due to the spines.

Gallery

File:Caesalpiniaceae - Parkinsonia aculeata-4.JPG, Shrub of ''Parkinsonia aculeata'' File:Caesalpiniaceae - Parkinsonia aculeata-1.JPG, Leaflets of ''Parkinsonia aculeata'' File:Caesalpiniaceae - Parkinsonia aculeata-2.JPG, Leaflets of ''Parkinsonia aculeata'' File:Caesalpiniaceae - Parkinsonia aculeata-3.JPG, Thorns on ''Parkinsonia aculeata'' File:Parkinsonia aculeata 3.jpg, Plant of ''Parkinsonia aculeata'' File:Parkinsonia aculeata flowers 3.jpg, Flowers of ''Parkinsonia aculeata''

References

*Cooperative Centre for Weed Management
Weed of the month - Parkinsonia aculeata
April 2005 *QLD Dept of Natural Resources and Mines, Land Protection. 2004
NRM facts pest series: Parkinsonia

* Pignatti S. - Flora d'Italia – Edagricole – 1982. Vol. I, pag. 625

External links

* *
Biolib: ''Parkinsonia aculeata''

Schede di Botanica: ''Parkinsonia aculeata''
{{Authority control

aculeata Aculeata is an infraorder of Hymenoptera containing ants, bees, and stinging wasps. The name is a reference to the defining feature of the group, which is the modification of the ovipositor into a stinger. However, many members of the group cann ...

Plants described in 1753 Taxa named by Carl Linnaeus North American desert flora Trees of Argentina Trees of Northern America Trees of Bolivia Trees of Ecuador Trees of Paraguay Trees of Peru Trees of Uruguay Flora of the Rio Grande valleys Flora of the Sonoran Deserts Flora of the Chihuahuan Desert Flora of the Mexican Plateau Flora without expected TNC conservation status