Wiwi
Botanical name: Ficinia nodosa
Synonyms: Scirpus nodosus; Isolepis nodosa; Scirpoides nodosa; Holoschoenus nodosus
Common name(s): Wiwi, Knobby Club Rush, Knotted Club Rush, Ethel Sedge
About:
Wiwi is a tough, evergreen rush-like sedge that forms dense clumps of upright green stems from stout underground rhizomes. Highly tolerant of salt spray, wind, drought and poor coastal soils, it is one of New Zealand’s best native plants for stabilising sand dunes and exposed coastal sites. The rounded brown flower heads remain attractive for many months, providing year-round structure in the landscape.
Natural habitat:
Common in coastal dunes, sandy beaches, estuaries, saltmarshes, rocky shores and open coastal habitats. Occasionally extends inland into montane areas and can be found on sandstone, limestone and volcanic outcrops.
Growing environment:
Sun, Coastal, Salt, Wind, Frost & Free draining tolerant.
Endemic distribution:
Native to New Zealand, Australia, South Africa and many other Southern Hemisphere regions.
In New Zealand it occurs throughout the Kermadec, Three Kings, North, South, Stewart and Chatham Islands.
Height:
15 cm–2 m
Width:
60 cm–2 m
Flowering:
September – December
Produces rounded light brown flower heads held just below the stem tip.
Fruiting:
November – May
Develops small glossy dark brown to black nuts that are dispersed naturally by wind.
Uses:
• Coastal restoration
• Sand dune stabilisation
• Erosion control
• Wetland margins
• Rain gardens
• Biofiltration systems
• Mass landscape planting
• Native gardens
Appearance:
Growth habit:
A dense, clump-forming perennial with numerous upright, rush-like stems arising from a stout woody rhizome.
Leaves:
Leaves are reduced to reddish-brown basal sheaths, with the green cylindrical stems performing the plant’s main photosynthetic function.
Flowers:
Rounded hemispherical flower heads sit just below the pointed continuation of each stem, creating the characteristic “knotted” appearance.
Fruit:
Tiny glossy dark brown to black nuts develop within the persistent flower heads and often remain on the plant for many months.
Ecology:
An important coastal stabilising species that binds sand and protects dunes from erosion. It provides shelter for native invertebrates and contributes to healthy estuarine and coastal ecosystems. The species is also increasingly used in constructed wetlands and biofiltration systems for removing excess nutrients from stormwater.
Associated habitats:
Sand dunes, coastal beaches, estuaries, saltmarshes, coastal cliffs, rocky shores, wetlands, seepages and occasionally montane grasslands.
How to grow:
Plant in full sun in free-draining sandy or gravelly soils. Exceptionally tolerant of salt spray, wind, drought and frost once established. Also performs well around ponds, rain gardens and wetland margins provided drainage is not permanently stagnant.
Propagation:
Very easy to grow from fresh seed or by division of established clumps. Plants establish quickly and require little maintenance once established.
Cultural use:
Traditionally, Māori used wiwi and related sedges as roofing material for wharenui and other woven applications. Today it remains an important species in coastal restoration and ecological engineering projects.
Garden value:
Wiwi is one of New Zealand’s most versatile native architectural plants. Its clean upright form, evergreen foliage and remarkable tolerance of harsh coastal conditions make it ideal for modern landscapes, coastal gardens, rain gardens and large-scale restoration projects where year-round texture and durability are essential.