wires up the coastal salt marsh edges

Size
Height: 40–80 cm
Lifespan
5–10 years
Diet
Not applicable (rush). Photosynthetic.
Habitat
Salt marshes, estuaries, tidal flats and coastal wetlands. Prefers saline or brackish soils with full sun. Tolerates salt spray, wind and occasional inundation.
Range
Coastal areas of the North and South Islands from Northland to Otago. Most common in salt marshes, estuaries and coastal wetlands.
Endemism
Endemic
Main Threats
Habitat loss from coastal development is the primary threat. Climate change affecting coastal habitats and sea level rise. Water pollution and degradation.
Population
Populations are considered stable but localised. The species is common in salt marshes throughout its range. It is threatened by ongoing coastal development. Protection of coastal wetlands is important.
Conservation Status
Not Threatened
Human Risk
caution
Handling Note
sharp sedge leaves cause skin lacerations, wear long pants when walking through
Conservation Note
Endemic rush; widespread in coastal and wetland habitats throughout New Zealand.
Assessment
NZTCS Vascular Plants (2023)
Te Ao Māori
In Māori tradition, oioi was valued for its tough, jointed stems. The stems were used for weaving floor coverings (whāriki), baskets (kete) and fish traps (hīnaki). The joints were noted. The name oioi refers to the jointed, nodding stems. Oioi was an important resource for coastal iwi. A plant of the salt marshes. Gathered by those who knew the tidal places.
Sharp sedge leaves cause skin lacerations. Wear long pants when walking through. Oioi is a distinctive jointed rush. It grows in salt marshes and estuaries. Its stems are dark green and have distinctive joints, like bamboo. It forms dense clumps that provide habitat for birds and fish. The stems are tough and durable. They are able to withstand the salt and the tide. A plant that lives where fresh and salt water argue. The stems are hollow and jointed. They have a smooth surface. The joints are spaced at regular intervals. This gives the plant a segmented appearance. The leaves are reduced to sheaths at the joints. The plant is wind-pollinated. The seeds are dispersed by wind and water. Oioi is an important plant for stabilising estuarine margins. Its dense root system holds the soil together. This prevents erosion. The clumps also trap sediment. This helps to build the salt marsh. This works for now. The plant was used by Māori for weaving floor coverings, baskets and fish traps. The stems are tough and durable. They are resistant to rot. They were soaked to soften them before weaving. To find oioi is to walk the edges of salt marshes and estuaries. Look for the dense clumps of jointed, dark green stems. The stems nod in the wind. Their joints click together. It is a plant of the salty places. A survivor of the tidal zone. That is oioi. Jointed, tough, and salt-tolerant. It holds the estuary together. No one told it otherwise. Populations are considered stable but localised. The species is common in salt marshes throughout its range. It is threatened by ongoing coastal development. Habitat loss from coastal development is the primary threat. Climate change affects coastal habitats and sea level rise. Water pollution and degradation are also threats. Protection of coastal wetlands is important.