Lygodium articulatum or mangemange is a creeping fern, the woody stems of which, according to John Dawson and Rob Lucas in their book Nature Guide to the New Zealand Forest, are technically fronds.
These twining growths head up for the light and often reach the forest canopy, while the true stems remain low.
Leaves are shiny and green – the leaflets that fork many times are fertile, while the ones that fork 2 to 3 times are sterile. Leaves can be anywhere along the vines but there’s often a mass up out of sight.
Bushman’s mattress is found from North Cape to the Bay of Plenty in the North Island, but take care not to confuse the common name with the shrub Muehlenbeckia complexa, sometimes called mattress plant.
The NZ Plant Conservation Network entry for Lygodium articulatum explains its common name: “These interwoven tangles make an excellent mattress and many a tramper has used these when caught out in the northern forests for the night. The only problem is that they are also a favoured home of tree weta, as many-a-tramper-caught-out-in-the-northern-forest-for-the-night comes to appreciate!”
Early writers recorded Maori using the vines in a variety of ways – to bind thatch securely on roofs; lashing in storehouse construction; to construct fish traps and eelpots; naturally curved stems, hardened by fire, as fish hooks; and to tie the necks of sacks used for soaking fermenting corn (after maize was introduced to New Zealand Maori developed a method of preserving it by soaking cobs in running water for 6 weeks to 3 months – the resulting (stinky) kānga pirau was made into porridge).
From an article at the Oratia Native Plant Nursery website: “Mangemange is the only New Zealand species in the genus, but about 30 or 40 related species occur throughout the tropics and some such as mangemange grow into the temperate zone. Many have been declared noxious weeds overseas, where they have been taken out of their natural environment and introduced into other parts of the world without their natural predators.”