Talk to anyone about New Zealand and the three things that they will mention are the All Blacks, a kiwi and the silver fern.
We have an unusually high number of fern species for a temperate country and about 40 per cent of these species occur nowhere else in the world.
The leaves of ferns are called fronds and when they are young they are tightly coiled into a tight spiral. This shape, called a ‘koru’ in Māori, is a popular motif in many New Zealand designs.
Ferns can be categorised based on their growth form such as tufted, creeping, climbing, perching and tree ferns.
One notable New Zealand fern is bracken (rārahu), which grows in open, disturbed areas and was a staple of the early Māori diet in places too cold for the kümara to grow. The roots were gathered in spring or early summer and left to dry before they were cooked and eaten.
The silver fern or ponga is a national symbol and is named for the silver underside of its fronds.
The mamaku is New Zealand’s tallest tree fern, growing up to 20 m high.
Wheki is another type of tree fern that can be distinguished by its hairy koru and ‘skirt’ of dead, brown fronds hanging from under the crown. It often forms groves by means of spreading underground rhizomes, which give rise to several stems.
Most ferns reproduce sexually, but some ferns also have efficient means of vegetative reproduction, such as the underground stems of bracken and the tiny bulblets that grow on the surface of fronds of the hen-and-chicken fern.