Parkinsonia aculeata
Encyclopedia
Parkinsonia aculeata is a species of perennial flowering
tree
in the pea
family, Fabaceae
. Common names include palo verde, Mexican palo verde, Parkinsonia, Jerusalem thorn, and (where?) jelly bean tree.
(1567–1650), while the species Latin name aculeata refers to the thorny stem of this plant.
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 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
7–12 mm (0.275590551181102–0.47244094488189 in) long at the axils of the leaves. The flower
s are yellow- orange and fragrant, 20 mm (0.78740157480315 in) 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 the middle months of spring(March& April or September & October). The flowers are pollinated by bees. The fruit
is a seedpod, leathery in appearance, light brown when mature.
in Australia
, parts of tropical Africa
, Hawaii
, and other Islands
in the Pacific Ocean
.
It was introduced to Australia as an ornamental tree and for shade around 1900. It is now a serious weed
widespread through Western Australia
, the Northern Territory
and Queensland
, covering about 8000 km² (3,088.8 sq mi) of land, and has the potential to spread through most of the semi-arid to subhumid tropical area in Australia.
It forms dense thicket
s, preventing access for humans, native animals and livestock
to waterways. The fruits (seedpods) float, and the plant spreads by dropping pods into water, or pods are washed downstream by seasonal flood
ing. Without the scarifing 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
s have been introduced
to Australia for biological control; the parkinsonia bean weevil
s, Penthobruchus germaini and Mimosestes ulkei, both have larva
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
tissues but has had little overall impact on the plant. Fire is effective for young trees; mechanical removal and herbicide
s are also used.
(western Texas
, southern New Mexico
southern Arizona
), and northern Mexico
(Sonora
and Chihuahua
). It has been moved by humans into the Caribbean
, South America
south to northern Argentina
, and the Galápagos Islands
. It has been introduced in Europe
and it is widespread in Australia
. This thin barked species does not become established in areas where weather dips below 20 degrees F.
Flowering plant
The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...
tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...
in the pea
Pea
A pea is most commonly the small spherical seed or the seed-pod of the pod fruit Pisum sativum. Each pod contains several peas. Peapods are botanically a fruit, since they contain seeds developed from the ovary of a flower. However, peas are considered to be a vegetable in cooking...
family, Fabaceae
Fabaceae
The Fabaceae or Leguminosae, commonly known as the legume, pea, or bean family, is a large and economically important family of flowering plants. The group is the third largest land plant family, behind only the Orchidaceae and Asteraceae, with 730 genera and over 19,400 species...
. Common names include palo verde, Mexican palo verde, Parkinsonia, Jerusalem thorn, and (where?) jelly bean tree.
Etymology
The genus name Parkinsonia honors the English botanist John ParkinsonJohn Parkinson
John Parkinson may refer to:*John Parkinson , English herbalist*John B. Parkinson , American architect in Los Angeles*John Parkinson , British Labour Party MP for Wigan, 1918–1941...
(1567–1650), while the species Latin name aculeata refers to the thorny stem of this plant.
Description
Parkinsonia aculeata may be a spiny shrub or a small tree. It grows 2 to 8 m (6.6 to 26.2 ft) high, with a maximum height of 10 metres (32.8 ft). Palo verde may have single or multiple stems and many branches with pendulous leaves. The leavesLeaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
and stems are hairless
Trichome
Trichomes are fine outgrowths or appendages on plants and certain protists. These are of diverse structure and function. Examples are hairs, glandular hairs, scales, and papillae.- Algal trichomes :...
. The leaves are alternate and pennate (15 to 20 cm long). The flattened petiole
Petiole (botany)
In botany, the petiole is the stalk attaching the leaf blade to the stem. The petiole usually has the same internal structure as the stem. Outgrowths appearing on each side of the petiole are called stipules. Leaves lacking a petiole are called sessile, or clasping when they partly surround the...
is edged by two rows of 25–30 tiny oval leaflets; the leaflets are soon deciduous
Deciduous
Deciduous means "falling off at maturity" or "tending to fall off", and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe...
in dry weather (and during the winter in some areas) leaving the green petioles and branches to photosynthesize
Photosynthesis
Photosynthesis is a chemical process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Photosynthesis occurs in plants, algae, and many species of bacteria, but not in archaea. Photosynthetic organisms are called photoautotrophs, since they can...
.
The branches grow double or triple sharp spines
Thorns, spines, and prickles
In botanical morphology, thorns, spines, and prickles are hard structures with sharp, or at least pointed, ends. In spite of this common feature, they differ in their growth and development on the plant; they are modified versions of different plant organs, stems, stipules, leaf veins, or hairs...
7–12 mm (0.275590551181102–0.47244094488189 in) long at the axils of the leaves. The flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s are yellow- orange and fragrant, 20 mm (0.78740157480315 in) 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 the middle months of spring(March& April or September & October). The flowers are pollinated by bees. The fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
is a seedpod, leathery in appearance, light brown when mature.
Invasive problems
P. aculeata is a major invasive speciesInvasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
in Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, parts of tropical Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
, Hawaii
Hawaii
Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...
, and other Islands
Pacific Islands
The Pacific Islands comprise 20,000 to 30,000 islands in the Pacific Ocean. The islands are also sometimes collectively called Oceania, although Oceania is sometimes defined as also including Australasia and the Malay Archipelago....
in the Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
.
It was introduced to Australia as an ornamental tree and for shade around 1900. It is now a serious weed
Invasive species in Australia
Invasive species are a serious threat to the native biodiversity of Australia and are an ongoing cost to Australian agriculture.Management and the prevention of the introduction of new invasive species are key environmental and agricultural policy issues for the Australian federal and state...
widespread through Western Australia
Western Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
, the Northern Territory
Northern Territory
The Northern Territory is a federal territory of Australia, occupying much of the centre of the mainland continent, as well as the central northern regions...
and Queensland
Queensland
Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...
, covering about 8000 km² (3,088.8 sq mi) of land, and has the potential to spread through most of the semi-arid to subhumid tropical area in Australia.
It forms dense thicket
Thicket
A thicket is a very dense stand of trees or tall shrubs, often dominated by only one or a few species, to the exclusion of all others. They may be formed by species that shed large amounts of highly viable seeds that are able to germinate in the shelter of the maternal plants.In some conditions the...
s, preventing access for humans, native animals and livestock
Livestock
Livestock refers to one or more domesticated animals raised in an agricultural setting to produce commodities such as food, fiber and labor. The term "livestock" as used in this article does not include poultry or farmed fish; however the inclusion of these, especially poultry, within the meaning...
to waterways. The fruits (seedpods) float, and the plant spreads by dropping pods into water, or pods are washed downstream by seasonal flood
Flood
A flood is an overflow of an expanse of water that submerges land. The EU Floods directive defines a flood as a temporary covering by water of land not normally covered by water...
ing. Without the scarifing 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
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s have been introduced
Introduced species
An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
to Australia for biological control; the parkinsonia bean weevil
Bean weevil
The bean weevils or seed beetles are a subfamily of beetles, now placed in the family Chrysomelidae, though they have historically been treated as a separate family. They are granivores, and typically infest various kinds of seeds or beans, living for most of their lives inside a single seed...
s, Penthobruchus germaini and Mimosestes ulkei, both have larva
Larva
A larva 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...
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
Photosynthesis is a chemical process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Photosynthesis occurs in plants, algae, and many species of bacteria, but not in archaea. Photosynthetic organisms are called photoautotrophs, since they can...
tissues but has had little overall impact on the plant. Fire is effective for young trees; mechanical removal and herbicide
Herbicide
Herbicides, also commonly known as weedkillers, are pesticides used to kill unwanted plants. Selective herbicides kill specific targets while leaving the desired crop relatively unharmed. Some of these act by interfering with the growth of the weed and are often synthetic "imitations" of plant...
s are also used.
Distribution
P. aculeata is native to the Sonoran and Chihuahan Deserts of southwestern United StatesSouthwestern United States
The Southwestern United States is a region defined in different ways by different sources. Broad definitions include nearly a quarter of the United States, including Arizona, California, Colorado, Nevada, New Mexico, Oklahoma, Texas and Utah...
(western Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
, southern New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
southern Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
), and northern Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
(Sonora
Sonora
Sonora officially Estado Libre y Soberano de Sonora is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided into 72 municipalities; the capital city is Hermosillo....
and Chihuahua
Chihuahua
Chihuahua officially Estado Libre y Soberano de Chihuahua is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. Its capital city is Chihuahua....
). It has been moved by humans into the Caribbean
Caribbean
The Caribbean is a crescent-shaped group of islands more than 2,000 miles long separating the Gulf of Mexico and the Caribbean Sea, to the west and south, from the Atlantic Ocean, to the east and north...
, South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
south to northern Argentina
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
, and the Galápagos Islands
Galápagos Islands
The Galápagos Islands are an archipelago of volcanic islands distributed around the equator in the Pacific Ocean, west of continental Ecuador, of which they are a part.The Galápagos Islands and its surrounding waters form an Ecuadorian province, a national park, and a...
. It has been introduced in Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
and it is widespread in Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
. This thin barked species does not become established in areas where weather dips below 20 degrees F.