Pouteria costata
Encyclopedia
Pouteria costata is a small coastal tree native to the northern North Island
(New Zealand
) and to Norfolk Island
(Australia
). In New Zealand, its common name is Tawapou (Tawāpou in Māori
); on Norfolk Island it is called Bastard Ironwood. The name costata is from the Latin costatus (ribbed), a reference to the prominently raised primary nerves of the leaves. Pouteria
is a genus of approximately 300 species in the tropics of America, Asia, Australia and the Pacific. A Pouteria species found in other Pacific Islands is sometimes erroneously included in P. costata.
, others prefer the genus Planchonella
(the latter genus is often sunk into the former). Other scientific names of this plant include Pouteria novo-zelandica.
On Norfolk Island P. costata is an uncommon tree, occurring locally in forested areas and on Mt Pitt, and is listed as 'endangered' under the Australian Environment Protection and Biodiversity Conservation Act 1999
. In New Zealand, Pouteria costata grows locally on islands and headlands along the northern coasts of the North Island
, from North Cape
to Tolaga Bay
(38° S) on the east coast, but only as far as the Manukau Harbour
(37° S) on the west, growing in association with pōhutukawa, karaka and taraire. It grows from sea level to about 450 m, always close to the sea. It is not regarded as threatened in New Zealand.
, the New Zealand pigeon, and the kākā
parrot, both of which were represented on Norfolk Island by closely related birds which are now extinct.
The fruit and seeds of P. costata are very palatable to rats. Research in New Zealand has shown that the eating of the fruit and the destruction of the seeds by kiore (Pacific rats) has substantially reduced the population of the tree and significantly altered the composition of coastal forest of the northern North Island. Kiore were introduced by Māori sometime in the last 1,000 years and became widespread on the three main islands, and reached many of the offshore islands. Tawapou seedlings and saplings are now rare on the mainland and on off-shore islands where kiore are present, and abundant on islands where they are absent. Where kiore are present, it is rare to find tawapou seeds that have not had their kernels removed. Kiore eat the flesh from freshly fallen tawapou fruit but tend to take the seeds to 'husking stations' where they remove the kernels. As many as 1,400 discarded husks have been found at a single site. The number of juvenile trees increases markedly on islands from which kiore have been removed. "The apparent thoroughness with which kiore find and eat the kernels before the seed germinates shows that kiore can substantially reduce seedling numbers… Numbers of tawapou, and the proportion of tawapou trees in forest vegetation, will increase after rat eradication on any island that still retains tawapou trees" (Campbell et al., 1999:280). Norfolk Island also has various species of rats, which no doubt contributes to the endangered status of P. costata there.
, and plant them on a the slopes of a nearby hill. From the rollers grew a grove of tawapou (P. costata) trees that today serve as a memorial of the arrival of the canoe. Similar stories are told of groves of tawapou trees at Houhoura Harbour and Aurere Beach. The Mamaru canoe, whose descendants live around Doubtless Bay and near Kaitaia
, carried in its crew an important ancestor named Pou. It is possible that the word 'tawapou' derives from 'Tawa-a-Pou' 'the Tawa trees of Pou'. A legend from East Cape relates to the Takitimu canoe, which was followed by a flock of Kākā
parrots as it left Hawaiki. They gorged on tawapou berries to sustain them on the long flight. When they reached East Cape they disgorged the seeds, which grew, and eventually the tawapou trees spread along the coast.
North 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...
(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...
) and to Norfolk Island
Norfolk Island
Norfolk Island is a small island in the Pacific Ocean located between Australia, New Zealand and New Caledonia. The island is part of the Commonwealth of Australia, but it enjoys a large degree of self-governance...
(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...
). In New Zealand, its common name is Tawapou (Tawāpou in Māori
Maori language
Māori or te reo Māori , commonly te reo , is the language of the indigenous population of New Zealand, the Māori. It has the status of an official language in New Zealand...
); on Norfolk Island it is called Bastard Ironwood. The name costata is from the Latin costatus (ribbed), a reference to the prominently raised primary nerves of the leaves. Pouteria
Pouteria
Pouteria is a genus of flowering trees in the gutta-percha family, Sapotaceae. The genus is widespread throughout the tropical regions of the world. It includes the Canistel , the Mamey Sapote and the Lúcuma...
is a genus of approximately 300 species in the tropics of America, Asia, Australia and the Pacific. A Pouteria species found in other Pacific Islands is sometimes erroneously included in P. costata.
Naming and taxonomy
Tawapou has undergone several scientific name changes. Some taxonomists consider it to belong in the wastebasket genus PouteriaPouteria
Pouteria is a genus of flowering trees in the gutta-percha family, Sapotaceae. The genus is widespread throughout the tropical regions of the world. It includes the Canistel , the Mamey Sapote and the Lúcuma...
, others prefer the genus Planchonella
Planchonella
Planchonella is a genus of flowering trees in the gutta-percha family, Sapotaceae. Named in honour of Jules Émile Planchon, it contains around 100 mainly tropical species, two of which reach South America and about 18 make it to Australia. It was described by Jean Baptiste Louis Pierre...
(the latter genus is often sunk into the former). Other scientific names of this plant include Pouteria novo-zelandica.
Distribution
Environment Protection and Biodiversity Conservation Act 1999
The Environment Protection and Biodiversity Conservation Act 1999 is an Act of the Parliament of Australia that provides a framework for protection of the Australian environment, including its biodiversity and its natural and culturally significant places...
. In New Zealand, Pouteria costata grows locally on islands and headlands along the northern coasts of the North Island
North 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...
, from North Cape
North Cape, New Zealand
North Cape is located at the northern end of the North Auckland Peninsula in the North Island of New Zealand . It is the northeastern tip of the Aupouri Peninsula and lies 30 km east of Cape Reinga. The name is sometimes used to refer just to the cape which is known in Māori as Otou and which...
to Tolaga Bay
Tolaga Bay
Tolaga Bay is both a bay and small town on the East Coast of New Zealand's North Island located 45 kilometres northeast of Gisborne and 30 kilometres south of Tokomaru Bay.It was named Tolaga Bay by Lt...
(38° S) on the east coast, but only as far as the Manukau Harbour
Manukau Harbour
Manukau Harbour is the second largest natural harbour in New Zealand by area. It is located to the southwest of the Auckland isthmus, and is an arm of the Tasman Sea.-Geography:...
(37° S) on the west, growing in association with pōhutukawa, karaka and taraire. It grows from sea level to about 450 m, always close to the sea. It is not regarded as threatened in New Zealand.
Description
P. costata is fairly slow growing, closely branched tree that prefers coastal conditions. It grows up to 20 m tall with a trunk to 1 m in diameter. The bark is rough and varies in colour from grey to brownish-grey. It prefers semi-shade, and is frost tender. The dark green lustrous leaves measure from 5 to 10 cm (sometimes up to 15 cm) long and 2 to 5 cm wide. The main vein in the centre of the leaf is distinct above and below, as are the primary veins on each side of it, which number from 14 to 20. The branchlets and leaf stems are covered with fine flattened hairs. The tiny, delicate flowers, only 4-6 mm in diameter, usually arise from the leaf axils, but also directly from the branchlets. The tree produces large multi-coloured berries 2.5 to 4 cm long which enclose 2 to 4 hard, hard, curved, almost polished seeds, almost as long as the berry, which were used by the Māori to make necklaces. The berries undergo successive stages of colour from green to orange to a very dark red as they ripen, a process that can take from 12 to 15 months. The berries are heavy and will fall from the tree easily if it is disturbed. According to Salmon, a tree with a heavy crop of berries is a spectacular sight (1973:278). When wounded, the tree exudes a sticky, white latex. The white-coloured wood is hard and durable. The fruit are consumed by the kererūKereru
The New Zealand Pigeon or kererū is a bird endemic to New Zealand. Māori call it Kererū in most of the country but kūkupa and kūkū in some parts of the North Island, particularly in Northland...
, the New Zealand pigeon, and the kākā
Kaka
The New Zealand Kaka, also known as Kākā, is a New Zealand parrot endemic to the native forests of New Zealand.-Description:...
parrot, both of which were represented on Norfolk Island by closely related birds which are now extinct.
Threats
In Māori culture
Tawapou logs were often used as rollers to help bring large canoes onshore. In Māori traditions of Northland, the canoe 'Waipapa' is said to have landed in Doubtless Bay. The captain asked his crew to take the rollers of the canoe, which had been carried from HawaikiHawaiki
In Māori mythology, Hawaiki is the homeland of the Māori, the original home of the Māori, before they travelled across the sea to New Zealand...
, and plant them on a the slopes of a nearby hill. From the rollers grew a grove of tawapou (P. costata) trees that today serve as a memorial of the arrival of the canoe. Similar stories are told of groves of tawapou trees at Houhoura Harbour and Aurere Beach. The Mamaru canoe, whose descendants live around Doubtless Bay and near Kaitaia
Kaitaia
Kaitaia is a town in the far north region of New Zealand, at the base of the Aupouri Peninsula which is about 160 km northwest of Whangarei. It is the last major settlement on the main road north to the capes and bays on the peninsula...
, carried in its crew an important ancestor named Pou. It is possible that the word 'tawapou' derives from 'Tawa-a-Pou' 'the Tawa trees of Pou'. A legend from East Cape relates to the Takitimu canoe, which was followed by a flock of Kākā
Kaka
The New Zealand Kaka, also known as Kākā, is a New Zealand parrot endemic to the native forests of New Zealand.-Description:...
parrots as it left Hawaiki. They gorged on tawapou berries to sustain them on the long flight. When they reached East Cape they disgorged the seeds, which grew, and eventually the tawapou trees spread along the coast.