Laurelia novae-zelandiae

Pukatea
Hutt River viewed from flume bridge, Kaitoke Park, Upper Hutt, surrounded by native bush with pukatea laurel.
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Magnoliids
Order:	Laurales
Family:	Atherospermataceae
Genus:	Laurelia
Species:	L. novae-zelandiae
Binomial name
Laurelia novae-zelandiae A.Cunn.

Laurelia novae-zelandiae, also called Pukatea, is a large laurifolia evergreen tree, endemic to the forests of New Zealand . with so-called 'toothed' leaves and producing small flowers. It is a species in the Atherospermataceae (formerly Monimiaceae) family, typical representative of Laurel forest ecoregion.

Distribution

Pukatea is generally found in lowland forest and grows throughout the North Island of New Zealand, and the northern third of the South Island. Requires plenty of moisture, many times in damp areas or on the edges of streams. It often grows in damp low-land forests, especially gullies. Rainy, moisty, damp places and swamps... the typical laurel forest habitat. The species is a laurifolia related with laurel forest species of Australia, New Caledonia and Valdivian laurel forest of Sudamerica, through the connection of the Antarctic flora. The Laurelia genus, contains only two species, both endemic to the southern hemisphere, an example of Gondwanan distribution. Other one is Laurelia sempervirens native to Chile.

The tree is endemic to New Zealand, is widespread in mainly coastal situations. 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, grows well in poorly drained soil but is equally at home on hillsides. Pukatea require a warm subtropical to tropical climate cool but also frost-free or with only very slight winter frosts not below -4°C, and with high summer heat, rainfall, and humidity. Growth is best on well-drained, slightly acidic soils rich in organic matter.

Description

This species is very similar to Bay Laurel, Laureliopsis philippiana, Laurelia sempervirens and others lauroides. Pukatea can slowly grow to a height of 40 m, usually 35 m, and is the only New Zealand native tree developing large plank-buttresses to support the tree's growth in swamp or shallow-soil areas. Also it have specialized respiratory roots structure in certain waterlogged ground or mud named pneumatophores. These fragrant trees are characteristic of the lower strata of the tropical rainforest. The species is a conical resistant tree with thin bark and a pale brownish grey trunk that becomes attractively buttressed at the base. Its dark green glossy, elliptic leaves are 5-7 cm long and have coarsely serrated edges and paler undersides. The odorous opposite leaves, without shalls, have oil cells in the parenchyma, and brochidodromous nerves. It is a mostly dioecious species, male and female flowers are on separate individual specimens. Some specimens had a ratio as high as 100 male flowers to every female or hermaphrodite one. These results suggest that the species is not truly dioecious. The female and hermaphrodite flowers are very similar. The flowers are tiny, inconspicuous and in small racemes. The star-shaped flowers are whitish with yellow glistening glands and scarlet anther flaps. The glands at the base of the stamens in Laurelia novaezelandiae secrete nectar that accumulates at the base of the flower and makes a large number of bees, blowflies, small flightless animals and Bombyliidae visit flowers . The nectar is visible as a colourless liquid which gives a glistening appearance to the outer faces of the glands. Nectar runs down from the glands and accumulates on the floor of the flower as a result of continuing secretion. The fruit are little pear shaped capsules which contain numerous seeds attached to fine feathery anemophilous filaments which aid to disperse by wind. The seed of this species is dispersed by the wind (anemochory). The feathery achenes must keep moist when sown. Often, only a few seeds are viable.

Native bush with mature pukatea trees in Kaitoke Park, Upper Hutt

Uses

Historically, the light, but tough timber of pukatea has been used for boat building. The timber of Pukatea was used by Maori to create figureheads for canoes. It is rather soft, but very strong. It yields a pale hardwood that is difficult to split and that upon impact rather than to break, it dents. Its wood is pale-yellowish, with growth rings little notorious and homogeneous and fine texture. An extract from the bark containing the alkaloid pukateine is used in traditional Māori herbal medicine as an analgesic.. It was used by indigenous peoples to treat tuberculosis. The bark of Laurelia novae-zelandiae was used by Maori in a number of medical remedies but it was especially noted for its use against tubercular lesions. The pulp of the cambium was boiled in water and the resulting liquid used for treating tubercular ulcers.

Further reading

• "STUDIES ON THE MONIMIACEAE II.The Floral morphology of Laurelia novae-zelandiae A. Cunn. (SUBFAMILY ATHEROSPERMOIDEAE)" by F.B. Sampson, in New Zealand Journal of Botany, September 1969 Item 20: pages 214-240 - pdf format.