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 (Māori: "tawāpou"); 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. Naming and taxonomy Tawapou has undergone several scientific name changes. Some taxonomists consider it to belong in the wastebasket genus Pouteria, others prefer the genus Planchonella (the latter genus is often sunk into the former). Other scientific names of this plant include Pouteria novo-zelandica. Distribution 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, including the Three Kings 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. It grows in association with pohutukawa, 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 Pouteria 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,