Karaka (tree)
Encyclopedia
Karaka is an evergreen
laurifolia tree, of the family Corynocarpaceae, with large glossy leaves endemic
to New Zealand
, where it is widespread in mainly coastal situations, often forming a major component of coastal forest, although it is rarely a dominant tree. Sometimes Karaka occurs inland, usually the result of Māori plantings near former village sites.
and South Island
s to Banks Peninsula
(43°45′S) and Okarito (43°20′S), on the Three Kings Islands
, on Raoul Island
in the Kermadecs
, and on the Chatham Islands
. In the last two localities the presence of the tree is probably the result of Polynesian
plantings. The ecological requirements of the species, are those of the laurel forest
and like most of their counterparts laurifolia in the world, is a vigorous species with a great ability to populate the habitat that is conducive. Most botanists accept it as native only in the northern half of the North Island.
up to 1 metre in diameter. The thick, leathery leaves are dark green above and paler beneath, 50 to 200mm wide and 30 to 70 mm wide. The leaves are glossy. In winter and spring (August to November) it produces stout, erect panicles of tiny flower
s with petioles 10-15 mm long. The individual flowers are 4 to 5 mm in diameter, greenish-cream to off-white or pale yellow. The fruit is an ellipsoid to ovoid drupe 25 to 46 mm long, with pale yellow to orange flesh, and the seed is a single kernel. The fruit ripens in summer and autumn January to April and the seed dispersion is the result of scattering by columbiform birds mostly.
due to convergent evolution. Those plants are adapted to high rainfall and humidity. The patterns of speciation indicate that since the onset of aridification on the continents 15 million years ago, rainforest species diversified. One of the products of aridification is the isolation of populations and this likely caused the increase in the rate of speciation. This genus has species adapted to the laurel forest
habitat, so common in the Corynocarpaceae. The morphology of sclerophyllous species is divergent from humid tropical climate species. The greatest diversity of species and a greater presence of the genus is given in Cloud forest
and tropical rainforest in Asia
and Southeast Asia
.
Corynocarpaceae grows well in moist, well drained ground, and tolerate a variety of soil types, attained a maximun in tropical and wetter areas of distribution, but its pattern of speciation is resulting in some cases from the product of aridification of the habitat. Some endangered relict
species are living in temperate areas and are distributed in tropical and subtropical lowland forests and montane rainforest.
Corynocarpus laevigatus responded to favourable climatic periods and expanded across the available habitat adapting also to more extreme conditions but depending on favorable soil edaphic conditions. Corynocarpus laevigatus need an annual oscillation of the temperature moderated by the proximity of the ocean and resist bad frost.
A related vegetal community evolved millions of years ago on the supercontinent of Gondwana
, and species of this community are now found on several separate areas of the Southern Hemisphere
, including South America
, Africa
, New Zealand
, Australia
and New Caledonia
. These lauroide leaves plant communities are twofold to tropical climate and temperate climate, having the more temperate climate their origin in the named Antarctic flora
.
The toxicity of the fruit necessitates care when handling. This evergreen tree is a popular place for smaller birds to sleep in during the winter. It is of great value to birds and other fauna, including invertebrates that feed on their fruits and disperse their seeds. The fact to bear fruit in winter gives this plant a very important ecological value, being a good food source for many species, especially birds, at the station hard by the shortage of resources. These same fruits are considered toxic to mammalia. The seeds of Karaka also exhibit anitimicrobial activity against S. aureus and E.coli.
It has great ecological value because it is a rugged pioneer species that preserve and enriches the soil facilitating colonization by others. It is a ecological indicator of a well-preserved area, slightly degraded or recovering.
The pulp of the fruit is edible, although bitter, but the fresh kernels contain the lethal alkaloid
poison
karakin. Accounts from the 19th century record that extensive processing was used by Māori to convert the kernels to an edible form, and mention that if the processing was not done with the greatest care, poisoning would result with symptoms including violent convulsions and severe muscle spasms which could leave the limbs permanently fixed in contorted positions. Death resulted in a few cases.
Karaka may be easily grown from fresh seed, but cuttings are very difficult to strike. Young plants are frost-tender and sensitive to cold. The tree will often naturalise in suitable habitats. It is common in cultivation and widely available for sale both in New Zealand and in suitable climates elsewhere. It is regarded as a serious pest species in Hawaii
for native ecosystems.
On Chatham Islands this tree (local name - kopi) has played distinguished role in the history of Moriori
people: the soft bark of these trees has been used for making dendroglyph
s. In late 1998 there were remaining 147 known kopi trees with dendroglyphs.
Evergreen
In botany, an evergreen plant is a plant that has leaves in all seasons. This contrasts with deciduous plants, which completely lose their foliage during the winter or dry season.There are many different kinds of evergreen plants, both trees and shrubs...
laurifolia tree, of the family Corynocarpaceae, with large glossy leaves endemic
Endemic (ecology)
Endemism is the ecological state of being unique to a defined geographic location, such as an island, nation or other defined zone, or habitat type; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, all species of lemur are endemic to the...
to New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
, where it is widespread in mainly coastal situations, often forming a major component of coastal forest, although it is rarely a dominant tree. Sometimes Karaka occurs inland, usually the result of Māori plantings near former village sites.
Distribution
Karaka is widespread in mainly coastal situations. The tree is endemic to New Zealand, where the original distribution is unclear because of widespread planting by Maori and usually as the result of seed dispersal by birds or Maori plantations near old villages. The tree is common throughout the NorthNorth Island
The North Island is one of the two main islands of New Zealand, separated from the much less populous South Island by Cook Strait. The island is in area, making it the world's 14th-largest island...
and South Island
South Island
The South Island is the larger of the two major islands of New Zealand, the other being the more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman Sea, to the south and east by the Pacific Ocean...
s to Banks Peninsula
Banks Peninsula
Banks Peninsula is a peninsula of volcanic origin on the east coast of the South Island of New Zealand. It has an area of approximately and encompasses two large harbours and many smaller bays and coves...
(43°45′S) and Okarito (43°20′S), on the Three Kings Islands
Three Kings Islands
The Three Kings Islands or Manawa Islands are a group of 13 islands about northwest of Cape Reinga, the northernmost point of the North Island of New Zealand, where the South Pacific Ocean and Tasman Sea converge. They measure about 4.86 km² in area...
, on Raoul Island
Raoul Island
Anvil-shaped Raoul Island , the largest and northernmost of the main Kermadec Islands, , has been the source of vigorous volcanic activity during the past several thousand years that was dominated by dacitic explosive eruptions.The area of the island, including fringing islets and rocks...
in the Kermadecs
Kermadec Islands
The Kermadec Islands are a subtropical island arc in the South Pacific Ocean northeast of New Zealand's North Island, and a similar distance southwest of Tonga...
, and on the Chatham Islands
Chatham Islands
The Chatham Islands are an archipelago and New Zealand territory in the Pacific Ocean consisting of about ten islands within a radius, the largest of which are Chatham Island and Pitt Island. Their name in the indigenous language, Moriori, means Misty Sun...
. In the last two localities the presence of the tree is probably the result of Polynesian
Polynesians
The Polynesian peoples is a grouping of various ethnic groups that speak Polynesian languages, a branch of the Oceanic languages within the Austronesian languages, and inhabit Polynesia. They number approximately 1,500,000 people...
plantings. The ecological requirements of the species, are those of the laurel forest
Laurel forest
Laurel forest is a subtropical or mild temperate forest, found in areas with high humidity and relatively stable and mild temperatures. They are characterized by tree species with evergreen, glossy, enlongated leaves, known as laurophyll or lauroide...
and like most of their counterparts laurifolia in the world, is a vigorous species with a great ability to populate the habitat that is conducive. Most botanists accept it as native only in the northern half of the North Island.
Description
Karaka is a leafy canopy tree with erect or spreading branches. It grows to heights of up to 15 metres and has a stout trunkTrunk (botany)
In botany, trunk refers to the main wooden axis of a tree that supports the branches and is supported by and directly attached to the roots. The trunk is covered by the bark, which is an important diagnostic feature in tree identification, and which often differs markedly from the bottom of the...
up to 1 metre in diameter. The thick, leathery leaves are dark green above and paler beneath, 50 to 200mm wide and 30 to 70 mm wide. The leaves are glossy. In winter and spring (August to November) it produces stout, erect panicles of tiny 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 with petioles 10-15 mm long. The individual flowers are 4 to 5 mm in diameter, greenish-cream to off-white or pale yellow. The fruit is an ellipsoid to ovoid drupe 25 to 46 mm long, with pale yellow to orange flesh, and the seed is a single kernel. The fruit ripens in summer and autumn January to April and the seed dispersion is the result of scattering by columbiform birds mostly.
Ecology
Many botanical species are having similar foliage to the LauraceaeLauraceae
The Lauraceae or Laurel family comprises a group of flowering plants included in the order Laurales. The family contains about 55 genera and over 3500, perhaps as many as 4000, species world-wide, mostly from warm or tropical regions, especially Southeast Asia and South America...
due to convergent evolution. Those plants are adapted to high rainfall and humidity. The patterns of speciation indicate that since the onset of aridification on the continents 15 million years ago, rainforest species diversified. One of the products of aridification is the isolation of populations and this likely caused the increase in the rate of speciation. This genus has species adapted to the laurel forest
Laurel forest
Laurel forest is a subtropical or mild temperate forest, found in areas with high humidity and relatively stable and mild temperatures. They are characterized by tree species with evergreen, glossy, enlongated leaves, known as laurophyll or lauroide...
habitat, so common in the Corynocarpaceae. The morphology of sclerophyllous species is divergent from humid tropical climate species. The greatest diversity of species and a greater presence of the genus is given in Cloud forest
Cloud forest
A cloud forest, also called a fog forest, is a generally tropical or subtropical evergreen montane moist forest characterized by a persistent, frequent or seasonal low-level cloud cover, usually at the canopy level. Cloud forests often exhibit an abundance of mosses covering the ground and...
and tropical rainforest in Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
and Southeast Asia
Southeast Asia
Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...
.
Corynocarpaceae grows well in moist, well drained ground, and tolerate a variety of soil types, attained a maximun in tropical and wetter areas of distribution, but its pattern of speciation is resulting in some cases from the product of aridification of the habitat. Some endangered relict
Relict
A relict is a surviving remnant of a natural phenomenon.* In biology a relict is an organism that at an earlier time was abundant in a large area but now occurs at only one or a few small areas....
species are living in temperate areas and are distributed in tropical and subtropical lowland forests and montane rainforest.
Corynocarpus laevigatus responded to favourable climatic periods and expanded across the available habitat adapting also to more extreme conditions but depending on favorable soil edaphic conditions. Corynocarpus laevigatus need an annual oscillation of the temperature moderated by the proximity of the ocean and resist bad frost.
A related vegetal community evolved millions of years ago on the supercontinent of Gondwana
Gondwana
In paleogeography, Gondwana , originally Gondwanaland, was the southernmost of two supercontinents that later became parts of the Pangaea supercontinent. It existed from approximately 510 to 180 million years ago . Gondwana is believed to have sutured between ca. 570 and 510 Mya,...
, and species of this community are now found on several separate areas of the Southern Hemisphere
Southern Hemisphere
The Southern Hemisphere is the part of Earth that lies south of the equator. The word hemisphere literally means 'half ball' or "half sphere"...
, including 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...
, 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...
, New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
, 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...
and New Caledonia
New Caledonia
New Caledonia is a special collectivity of France located in the southwest Pacific Ocean, east of Australia and about from Metropolitan France. The archipelago, part of the Melanesia subregion, includes the main island of Grande Terre, the Loyalty Islands, the Belep archipelago, the Isle of...
. These lauroide leaves plant communities are twofold to tropical climate and temperate climate, having the more temperate climate their origin in the named Antarctic flora
Antarctic flora
The Antarctic flora is a distinct community of vascular plants which evolved millions of years ago on the supercontinent of Gondwana, and is now found on several separate areas of the Southern Hemisphere, including southern South America, southernmost Africa, New Zealand, Australia and New Caledonia...
.
The toxicity of the fruit necessitates care when handling. This evergreen tree is a popular place for smaller birds to sleep in during the winter. It is of great value to birds and other fauna, including invertebrates that feed on their fruits and disperse their seeds. The fact to bear fruit in winter gives this plant a very important ecological value, being a good food source for many species, especially birds, at the station hard by the shortage of resources. These same fruits are considered toxic to mammalia. The seeds of Karaka also exhibit anitimicrobial activity against S. aureus and E.coli.
It has great ecological value because it is a rugged pioneer species that preserve and enriches the soil facilitating colonization by others. It is a ecological indicator of a well-preserved area, slightly degraded or recovering.
The pulp of the fruit is edible, although bitter, but the fresh kernels contain the lethal alkaloid
Alkaloid
Alkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties. Also some synthetic compounds of similar structure are attributed to alkaloids...
poison
Poison
In the context of biology, poisons are substances that can cause disturbances to organisms, usually by chemical reaction or other activity on the molecular scale, when a sufficient quantity is absorbed by an organism....
karakin. Accounts from the 19th century record that extensive processing was used by Māori to convert the kernels to an edible form, and mention that if the processing was not done with the greatest care, poisoning would result with symptoms including violent convulsions and severe muscle spasms which could leave the limbs permanently fixed in contorted positions. Death resulted in a few cases.
Karaka may be easily grown from fresh seed, but cuttings are very difficult to strike. Young plants are frost-tender and sensitive to cold. The tree will often naturalise in suitable habitats. It is common in cultivation and widely available for sale both in New Zealand and in suitable climates elsewhere. It is regarded as a serious pest species in 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...
for native ecosystems.
On Chatham Islands this tree (local name - kopi) has played distinguished role in the history of Moriori
Moriori
Moriori are the indigenous people of the Chatham Islands , east of the New Zealand archipelago in the Pacific Ocean...
people: the soft bark of these trees has been used for making dendroglyph
Dendroglyph
In the Chatham Islands the indigenous Moriori people practiced the art of momori rakau as a ritual possibly associated with death or remembrance. Many scholars over the years have tried to penetrate the reasons behind these incisions into the trunks of the kopi trees and none have come up with a...
s. In late 1998 there were remaining 147 known kopi trees with dendroglyphs.