What are ferns?
Ferns are a very ancient family of plants: early fern fossils predate the beginning of the Mesozoic era, 360 million years ago. They are older than land animals and far older than the dinosaurs. They were thriving on Earth for two hundred million years before the flowering plants evolved.
As we know them now, most ferns are leafy plants that grow in moist areas under forest canopy. They are "vascular plants" with well-developed internal vein structures that promote the flow of water and nutrients. Unlike the other vascular plants, the flowering plants and conifers, where the adult plant grows immediately from the seed, ferns reproduce from spores and an intermediate plant stage called a gametophyte.
What makes them different from other vascular plants?
There are two answers to this.
The first is that ferns are (relatively) delicate plants that only grow in areas where there are suitably moist conditions. They favour sheltered areas under the forest canopy, along creeks and streams and other sources of permanent moisture. They cannot grow readily in hot dry areas like flowering plants and conifers.
The second explanation ties in with the first: ferns reproduce differently from the conifers and flowering plants. It all has to do with moisture. Not just the moisture that allows the plant to live where it does, but the moisture that allows it to reproduce there.
Ferns are a very ancient family of plants: early fern fossils predate the beginning of the Mesozoic era, 360 million years ago. They are older than land animals and far older than the dinosaurs. They were thriving on Earth for two hundred million years before the flowering plants evolved.
As we know them now, most ferns are leafy plants that grow in moist areas under forest canopy. They are "vascular plants" with well-developed internal vein structures that promote the flow of water and nutrients. Unlike the other vascular plants, the flowering plants and conifers, where the adult plant grows immediately from the seed, ferns reproduce from spores and an intermediate plant stage called a gametophyte.
What makes them different from other vascular plants?
There are two answers to this.
The first is that ferns are (relatively) delicate plants that only grow in areas where there are suitably moist conditions. They favour sheltered areas under the forest canopy, along creeks and streams and other sources of permanent moisture. They cannot grow readily in hot dry areas like flowering plants and conifers.
The second explanation ties in with the first: ferns reproduce differently from the conifers and flowering plants. It all has to do with moisture. Not just the moisture that allows the plant to live where it does, but the moisture that allows it to reproduce there.
Fun Facts
- 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 metres 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 (see below), 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.