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|Māori names||pīngao, pīkao (Ngāi Tahu)|
|Other common names||golden sand sedge|
|Scientific name||Ficinia spiralis (previously known as Desmoschoenus spiralis)|
|Family||Cyperaceae (sedge family)|
Pīngao, the golden sand sedge, was once common on sand dunes throughout New Zealand. Weavers love to use pīngao for patterning highlights. The orange-gold leaves provide a vibrant contrast to the black-dyed or natural pale hues of harakeke and kiekie. A familiar sight is pīngao combined with kākaho, kiekie and harakeke in tukutuku panels on the walls of wharenui. The leaves are also used on their own or with other weaving materials to make fine plaited kete (bags), whāriki (mats), pōtae (hats), pare (headbands), belts and raincapes.
Pīngao is a stout, grass-like plant, 30–90 cm tall, from the sedge family, found on active sand dunes. It is found only in New Zealand and is easily distinguished from other species that grow on sand dunes.
Most plants produce long, prostrate, tough rope-like stems (rhizomes) that creep along the sand surface until buried by shifting sand, leaving just the upper portion of leaves exposed. Some southern South Island populations produce dense tussock-like plants without extensive rhizomes.
Numerous tough, roughly textured leaves are borne in dense tufts on well-spaced, short, upright stems (tillers), along the length of rhizomes. The narrow leaves are 2–5 mm wide, with colour ranging from green through yellow to orange. Seen from a distance, pīngao patches have a distinctive orange hue. The length, width and strength of the leaves for weaving vary among pīngao populations growing in different areas.
Small, dark brown flowers appear in spring and are arranged spirally in tight clusters around the upper 10–30 cm of the upright stem (culm), interspersed with leaf-like bracts. The seeds are shiny, dark brown, egg-shaped, 3–5 mm long, and ripen and fall in early summer.
Distribution, ecology and decline
Pīngao is usually found on the seaward faces of coastal foredunes. It is capable of growing closer to the shoreline than any other sand binder. Along with spinifex (Spinifex sericeus) in the North Island it is the most important of the native sand binders for building and stabilising coastal sand dunes.
Pīngao was formerly widely distributed and abundant around the coastline of mainland New Zealand, Stewart Island and the Chatham Islands. It has declined dramatically since European settlement and is now absent from much of the east coast of the North and South islands, and elsewhere is patchily distributed, and often still in decline.
Initially decline was a consequence of widespread burning, browsing and trampling by domestic stock and wild animals such as goats, possums and rabbits. The decline was accelerated by competition from introduced plants, particularly the aggressive sand-binder marram grass, and tree lupin, which were widely planted for dune stabilisation. Today coastal development, sand mining, damage from motor vehicles, and overharvesting for weaving continue to exacerbate pīngao’s plight.
Seedlings are uncommon, and are usually confined to damp hollows. They are vulnerable to summer drought and inundation by sand during storms.
Native birds and insects relish the presence of pīngao. The rare New Zealand dotterel, the New Zealand pipit and the Australasian harrier have been observed nesting amongst pīngao, which also is an important food source for several species of moth and butterfly.
Growing pīngao in the home garden
Restoration programmes are underway to rehabilitate dunes with pīngao and to provide a sustainable weaving resource.
However, pīngao does not need a sand dune to grow, and weavers can build up their own resources in a home or community garden. Pīngao will grow well in a wide range of moist, well-drained soils. Add sand to lighten heavy soils. Summer watering and application of mulching materials such as sawdust, leaf litter, bark or straw will maintain necessary moisture levels and suppress weed growth. A deep mulch will encourage long leaves, improving their utility for weaving. Although it will grow in semi-shade, full sun will develop the rich golden colours for which pīngao is prized. A light application of slow-release fertiliser will promote faster growth, reportedly up to a metre a year.
Plants can be grown from cuttings, by division, or from seed. Given its vulnerable status, collections from wild pīngao populations are best restricted to taking of seed.
Collect seed as soon as pīngao ripens in early summer (December–January), but avoid immature green seed. Older seed tends to develop dormancy that reduces germination. Rub the seed heads firmly to dislodge the mature seed. There is no need to separate the seed from the abundant scales that are also dislodged from seed heads.
Sprinkle seeds and debris onto a tray of seed raising mix, and cover with 3–5 mm of coarse sand or sieved potting mix. Keep moist but don’t overwater. Addition of a plastic sheet over the tray will help maintain humidity, but should be removed once the seed has germinated. Summer-sown seed will germinate in 11–20 days and seedlings will be ready for pricking out in 4–8 weeks.
Prick out into potting mix in root trainers or small individual pots, taking care not to deform the tap root, although long roots may be trimmed. Hold seedlings under cover through the winter. Place them outside to harden off once frosts have finished. They can be planted in the garden then, as long as they are well cared for and weeded often. Otherwise, replant the seedlings into larger pots or root trainers (the size of a 500-g yoghurt container), and leave until the next autumn, by which time they should be 40 cm tall.
Take cuttings from tips of actively growing shoots in midsummer, and include at least 40 mm of stem. Insert cuttings deeply into moist potting mix with the leaves trimmed to one-third of their original length. If kept moist, roots will appear within about 4 weeks. Cuttings can be planted out in 6–12 months.
Sustainable harvest of pīngao
Inappropriate harvesting methods have contributed to the decline of pīngao in many areas.
A method commonly used of cutting a whole leaf cluster from the rhizome, or wrenching the central portion of it by bending and pulling, is highly damaging to the vigour of the plant. Growing shoots are destroyed, and if many clusters are taken in this way, the plant dies. There is a lot of waste too, because many of the leaves harvested like this are not of weaving quality and are discarded.
The best way to harvest pīngao is to use sharp scissors or pruners to clip individual leaves of good quality from the leaf clusters. Using this technique, there is no waste and no effect on the health of the plant.
Bergin DO, Herbert JW 1998. Pīngao on coastal sand dunes. Guidelines for seed collection, propagation and establishment. CDVN Technical Bulletin No 1. New Zealand Forest Research Institute.
Nga Puna Waihanga 1991. Pīngao. The golden sand sedge. 32 p.
For further information on uses of pīngao, search Nga Tipu Whakaoranga – a database on traditional uses of New Zealand native plants.