''Parkinsonia aculeata'' is a species of

perennial A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...

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, including only woody plants with secondary growth, plants that are ...

in the

pea The pea is most commonly the small spherical seed or the seed-pod of the flowering plant species ''Pisum sativum''. Each pod contains several peas, which can be green or yellow. Botanically, pea pods are fruit, since they contain seeds and d ...

family,

Fabaceae The Fabaceae or Leguminosae,International Code of Nomenc ...

. 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 (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

and stems are

hairless Hairless, also known as H, is a well-characterized Drosophila gene. Since Hairless is a dominant loss of function mutation, many mutations to Hairless are embryonic lethal, but there are several viable hairless mutants. This specific Drosophila ...

. 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 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 Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored in c ...

. The branches grow double or triple sharp spines long at the axils of the leaves. The

flower A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...

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 that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in particu ...

is a

seedpod This page provides a glossary of plant morphology. Botanists and other biologists who study plant morphology use a number of different terms to classify and identify plant organs and parts that can be observed using no more than a handheld magnify ...

, leathery in appearance, light brown when mature.

Invasive problems

''P. aculeata'' is a major

invasive species An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

, 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 in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

Hawaii Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...

, and other Islands in the

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

. 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 that i ...

and for shade around 1900. It is now a serious weed widespread through

Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...

, the

Northern Territory The Northern Territory (commonly abbreviated as NT; formally the Northern Territory of Australia) is an states and territories of Australia, Australian territory in the central and central northern regions of Australia. The Northern Territory ...

and

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...

, covering about of land, and has the potential to spread through most of the semi-arid to subhumid tropical area in Australia. It forms dense thickets, preventing access for humans, native animals and

livestock Livestock are the domesticated animals raised in an agricultural setting to provide labor and produce diversified products for consumption such as meat, eggs, milk, fur, leather, and wool. The term is sometimes used to refer solely to animals ...

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 ( 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 an area of study of the discipline hydrol ...

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 pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...

s have been introduced to Australia for biological control; the parkinsonia bean weevils, ''Penthobruchus germaini'' and ''Mimosestes ulkei'', both have

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. The ...

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 process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored in c ...

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 weedkillers, 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 fo ...

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 region of the United States that generally includes Arizona, New Mexico, and adjacent portions of California, Colorado, Ne ...

and northern

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

south to Galapagos Islands and northern

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

. It has been introduced in

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

Pakistan Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's List of countries and dependencies by population, fifth-most populous country, with a population of almost 24 ...

and

Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , i ...

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''
{{Taxonbar, from=Q279482

aculeata Aculeata is a subclade 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 cannot ...

Plants described in 1753 Taxa named by Carl Linnaeus North American desert flora Trees of Argentina Trees of the Southwestern United States Trees of the South-Central United States Trees of Baja California Trees of Baja California Sur Trees of Bolivia Trees of Ecuador Trees of Paraguay Trees of Peru Trees of Uruguay Flora of the Rio Grande valleys Trees of Sonora Trees of Sinaloa Trees of Chihuahua (state) Trees of Coahuila Trees of Nuevo León Trees of Tamaulipas Flora of the Sonoran Deserts Flora of the Chihuahuan Desert Flora of the Mexican Plateau Flora without expected TNC conservation status