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.