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.
Pouteria costata is fairly slow growing, closely branched tree that prefers coastal conditions. It grows up to 20m tall with a trunk to 1m 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 5-10 cm long and 2-5 cm wide. 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. When wounded, the tree exudes a sticky, white latex. The white-coloured wood is hard and durable. The fruit are consumed by the kereru (New Zealand pigeon), and the kaka parrot, both of which were represented on Norfolk Island by closely related birds which are now extinct.