Lakeshore vegetation | The Te Waihora Co-Governance Group

What's growing on the lakeshore?

Te Waihora/Lake Ellesmere shoreline vegetation can be classified into three major groups:

low elevation, lake edge vegetation that is frequently submerged by the brackish lake water for example native musk herbfield
higher elevation, (occasionally submerged) lake edge saltmarsh vegetation such as glasswort herbfield and sea rush rushland
freshwater wetland species, like harakeke/flax and raupō/bullrush, found in the vicinity of freshwater inflows and springs.

Types of plant species for each:

Low elevation, lake edge vegetation is made up entirely of native plant species.
Higher elevation, lake edge saltmarsh vegetation generally contains a mix of native and exotic plant species.
Freshwater, wetland vegetation also contains a mix of native and exotic plants. However, in the absence of control, introduced species like willows can dominate lakeshore freshwater wetlands.

Although relatively small in area, lakeshore freshwater wetlands contain some rare and unusual species, including a native orchid and giant umbrella sedge.

Other flora species

Greenpark Sands an extremely rare habitat

Greenpark Sands is a nationally important area as it is the most extensive example of an extremely rare habitat type in Aotearoa - the saline lagoon margin on sandy soil. The Sands are more than 1km wide when the lake level is low and extend along 13 kilometres of the eastern lakeshore. The lower-elevation sand flats have a diverse assemblage of native wetland plants, from salt-loving halophytes such as glasswort to species like arrow grass that you may also find in freshwater wetlands.

Te Waihora/Lake Ellesmere lakeshore wetland vegetation was mapped following surveys carried out in the early 1980s, 2007 and 2017. Fourteen broad vegetation types were identified from these surveys.

Lakeshore wetland vegetation types were categorised by habitat (brackish wetland/freshwater wetland/dryland) and by canopy composition (native/exotic/mixed native-exotic).

Between the 1982 survey and 2007 survey there was approximately a 100 ha increase in total area of freshwater wetland vegetation and a corresponding decline in extent of brackish wetland vegetation on the lakeshore. However, following the 2017 survey, this trend had reversed.

Along its southern shore, Te Waihora/Lake Ellesmere is separated from the sea by Kaitorete Spit. As well as native lakeshore wetland vegetation, the Spit’s coastal dune and terrestrial dryland habitats also support native plants.

Four species you might see on a visit to Kaitorete are described below.

Kaitorete/woolly head

Kaitōrete woolly head (Craspedia)

If you’ve never come across the Kaitorete woolly head – Craspedia ‘Kaitorete’ – it’s hard to imagine what this rare and endangered plant might look like. As it turns out, it’s a nondescript specimen – low-growing and grey with soft, velvety leaves that look a little like rabbit ears. It could be easily overlooked. Craspedia is a genus of daisies commonly known as billy buttons or woolly heads. They’re native to Aotearoa New Zealand and Australia, where they grow in a wide variety of habitats from sea level to the alps. In Aotearoa New Zealand, they’re found from East Cape in the North Island, all the way down to Stewart Island and the Chathams. Of the 23 species, six are found in Aotearoa New Zealand, usually growing on coastal sand dunes, in wetlands and on greywacke rock scree.

Craspedia ‘Kaitorete’, is found only on Kaitorete Spit and is one of the rarest plants in Aotearoa New Zealand.

Bachelor’s buttons

Bachelor's buttons (Cotula coronopifolia)

There’s no missing the tiny wetland plant, bachelor’s buttons when it’s in full flower; it turns heads as its dramatic golden show spreads its way across low-lying areas around Te Waihora/Lake Ellesmere. Bachelor’s buttons (Cotula coronopifolia), is known by a host of common names – brass buttons, mud-disk, yellow-buttons and water buttons. It is native to South Africa but it has a wide spread along beaches, tidal flats and estuaries around the world.

Bachelor’s buttons produces a mass of tiny, yellow, button-like flowers held on slender stalks above the creeping, hairless succulent stem and fleshy green leaves.

They prefer muddy, anoxic wetlands and brackish water and are very salt tolerant. The plant has fat, fleshy leaves that store water during times of saline inundation.

Prostrate broom

Carmichaelia appressa, is endemic to the gravelly, sandy loam, the stabilised sand dunes and the ridges of sand along Kaitorete Spit. Prostrate broom (also known as appressed broom), is a fast-growing native shrub that grows to a height of around 0.3m and has a spread of 0.5m. From October to January it is distinguished by its dense, pea-like, scented white and purple flowers. It grows in sprawling yellow-green mounds of apparently leafless branches.

In 2012, it was listed as “At Risk – Naturally Uncommon” and unfortunately, its natural habitat on Kaitorete Spit is very susceptible to damage by off-road bikes and 4WD vehicles. However, a large part of its habitat is protected within a scientific reserve.

The Carmichaelia genus of New Zealand brooms includes 24 plant species belonging to the Fabaceae or legume family. All but one (Carmichaelia exsul), are native to Aotearoa New Zealand. The genus has a range of forms from trees to prostrate species a few centimetres high and mature plants are usually leafless, with stipules fusing into scales to replace leaves.

Carmichaelia are named after Captain Dugald Carmichael, a Scottish army officer, who studied Aotearoa New Zealand plants.

Image copyright: Steve Attwood

Leafless clematis

Leafless clematis (Clematis afoliata)

Aotearoa New Zealand has eight to 10 native clematis species. One of those is the leafless clematis (Clematis afoliata), which has made itself at home on Kaitorete Spit.

This peculiar, leafless species, in which the leaves only appear as spirally coiled petioles (leaf stalks), is often found in open, rocky scrublands in the southern half of the North Island and, in tussocky grasslands in the South Island.

Stems grow up to three metres long and are stiff, wiry and grooved. These stems often form large bundles with an appearance like a large tangle of wire or string. From October through November it features small, creamy-white flowers.

Although it is not threatened, the leafless clematis is under pressure from development in some areas. Competition with naturalised plants also poses a threat to regeneration in some places.