The natural range of the Pōhutukawa 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), where it once formed a continuous coastal fringe. By the 1990s pastoral farming and introduced pests had reduced Pōhutukawa forests by over 90 per cent. It also occurs naturally 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 (125 ft). The tree is renowned as a cliff-dweller, able to maintain a hold in precarious, near-vertical situations. Like its Hawaiian relative the ʻōhiʻa lehua (M. polymorpha), the Pōhutukawa has shown itself to be efficient in the colonisation of lava plains – notably on Rangitoto, a volcanic island in the Hauraki Gulf.
The Pōhutukawa grows up to 25 metres (82 ft) in height, with a dome-like spreading form. It usually grows as a multi-trunked spreading tree. Its trunks and branches are sometimes festooned with matted, fibrous arieal roots. The oblong, leathery leaves are covered in dense white hairs underneath.
The tree flowers from November to January with a peak in mid to late December (the southern hemishpere 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 geninic 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 Motiti Island in the Bay Of Plenty
