T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network


Gunnera tinctoria (Chilean rhubarb)

Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Core eudicots
Order: Gunnerales
Family: Gunneraceae
Genus: Gunnera
Species: G. tinctoria
Binomial name: Gunnera tinctoria
Synonyms: Gunnera chilensis, Gunnera scabra
Common name: Chilean rhubarb, Giant rhubarb

Gunnera tinctoria is a plant species native to both sides of the Andes from Colombia to Chile and neighbouring zones in Argentina. It is a clump-forming herbaceous perennial plant with stout horizontal rhizomes. It can grow up to two metres tall. The plant has massive umbrella sized leaves (>2.5m across) with stems up to two metres tall.
It has erect spikes of cone-shaped inflorescences (>1m) from spring to early summer, with small flowers. The fruits are orange. The number of seeds is estimated from 80.000 per seedhead to 250.000 per plant.
It has been introduced to many parts of the world as an ornamental and edible plant. In Southern Chile (at latitudes of 36º–42ºS) it is a delicacy associated with Mapuche Indian customs. The young petioles are commonly sold by street vendors and eaten raw, along with salt and chilli to enhance the flavour(E. Villouta pers. Comm. 2004). It is essentially unrelated to rhubarb, as the two plants belong into different orders, but looks similar from a distance and has similar culinary uses.
In some countries including New Zealand it has spread from gardens and is becoming a weed problem. All giant gunnera species and hybrids are pest plants along coastal cliffs, streambanks and wetlands. The large leaves suppress native plants growing underneath them. The large leaves of giant gunnera prevent other plants growing underneath them. Giant gunnera are tolerant of salt spray and a wide range of climatic and soil conditions, therefore they are very invasive.

Below is an article published Taranaki Daily News 11.1.2015
Native plants under threat from the invasive gunnera weed along Taranaki's coastline have found an ally in the Department of Conservation.
The department used a helicopter to spray the weeds along cliff tops in South Taranaki yesterday.
Gunnera was introduced to New Zealand in 1968 as a garden ornamental but is now endangering native plants. Jared Coombes, DOC biodiversity services ranger, said the weed was over-running native plants.
"The weeds are getting massive and if we don't do anything they will compete for space," he said. "Its leaves are so large, and it grows quite fast, so it will shade out the sun from the native species, and then the native species will die."
Coombes said the helicopter was used to spray the cliffs at Kaupokonui beach, because it was faster.
"We used to abseil the cliffs but we didn't always get everything and so by using the helicopter, it affords us to save dollars but also to make sure we get everything sprayed," he said.
"There are some rare and special plants that grow on these cliffs so it is important to remove the gunnera so we don't end up with a local extinction of certain plant species."
Coombes said the distribution of the weed extended from Opunake to Patea, and the Taranaki Regional Council pushes farmers to remove gunnera from their streams.
"You will find [gunnera] throughout rivers on the ringplain through Taranaki," Coombes said.

Gunnera tinctoria growing wild roadside upper Arawhata Road, Opunake, South Taranaki.


  

  

  

New leaves unfolding.
  

The cone-shaped inflorescences.