Whekī and whekī-ponga
There are several varieties of whekī and ponga ferns, growing 5–20 metres high. Whekī (rough tree fern) has peg-like extensions marking where old fronds have fallen off, and is found throughout New Zealand. Whekī-ponga (brown tree fern) is distinguishable by its large skirt of old brown fronds, and grows south of Auckland. Both provided building materials – the trunks were used for walls, and the fronds for roofs.
Ponga (silver fern) grows in the North Island and the east and north of the South Island. Its fronds have a distinctive silver underside. Māori laid them silver-side up as track markers – in the dark they were lit up by burning torches. The leaves of rangiora were used in the same way.
Mamaku tree ferns grow in damp gullies throughout New Zealand. Reaching 20 metres in height, they have oval-shaped frond scars on the trunk. The white pith of the trunk and the koru (new shoots) are edible, although slimy when first cut. Māori stripped the trunk’s outer layers so the slime could dry or drain away. The plant was then cut down and cooked whole. Alternatively, koru (new shoots) were hung to dry. Baking was the preferred way to cook mamaku, to separate the stringy fibres from the flesh. Although the taste is bland, the nutritional value is high.
Kātote (soft tree fern) grows throughout New Zealand and is half the size of mamaku. It was a favourite food of South Island tribes.