The Pōhutukawa (Metrosideros excelsa) is a coastal evergreen tree of the myrtle family that produces a brilliant display of red flowers made up of a mass of stamens. The Pōhutukawa is one of twelve Metrosideros species endemic to New Zealand.
The tree grows up to twenty metres
in height, with a dome-like spreading form. Its natural range is the coastal regions of the North Island
of New Zealand
, north of a line stretching from New Plymouth
(39° S) to Gisborne
(38° S). It also grows on the shores of lakes in the Rotorua
area. A giant Pōhutukawa at Te Araroa
on the East Coast is reputed to be the largest in the country, with a height of 20 metres and a spread of 38 metres. The tree is renowned as a cliff-dweller, able to maintain a hold in precarious, near-vertical situations. Some specimens have matted, fibrous aerial roots
. Like its Hawaiian relative the Ōhia lehua (M. polymorpha
), the Pōhutukawa has shown itself to be efficient in the colonisation of lava fields, notably on Rangitoto Island
, a volcano in Auckland Harbour.
The Pōhutukawa flowers from November to January with a peak in mid to late December (the southern hemisphere
summer), with brilliant crimson flowers covering the tree, hence the nickname New Zealand Christmas Tree
. There is variation between individual trees in the timing of flowering, and in the shade and brightness of the flowers. In isolated populations genetic drift
has resulted in local variation: many of the trees growing around the Rotorua lakes produce pink-shaded flowers, and the yellow-flowered cultivar "Aurea" descends from a pair discovered in 1940 on Mōtiti Island
in the Bay of Plenty
In New Zealand, the Pōhutukawa is under threat from browsing by the introduced common brushtail possum
which strips the tree of its leaves. A charitable conservation trust, Project Crimson, has the aim of reversing the decline of Pōhutukawa and other Metrosideros
species - its mission statement is "to enable pohutukawa and rata to flourish again in their natural habitat as icons in the hearts and minds of all New Zealanders".
The Pōhutukawa is popular in cultivation, and there are fine examples in most North Island coastal cities. Vigorous and easy to grow, the tree flourishes well south of its natural range, and has naturalised in the Wellington area and in the north of the South Island. The Pōhutukawa has been introduced to other countries with mild-to-warm climates, including south-eastern Australia and it has naturalised on Norfolk Island. In coastal California, it is a popular street and lawn tree. In parts of South Africa, the Pōhutukawa grows so well that it is regarded as an invasive species, it is also naturalising on coastal cliffs in the Sydney Region, Australia. Specimens occur in Spain as north as La Coruña. This tree has withstood temperatures as low as -7.3°C at Tresco, England.
- Metrosideros excelsa. New Zealand Plant Conservation Network. Retrieved on 2007-06-09..
- Pohutukawa Fact Sheet. Project Crimson. Retrieved on 2007-06-09..
- Simpson, P., 2005. Pōhutukawa & Rātā: New Zealand's Iron-Hearted Trees. Wellington: Te Papa Press.