Gunnera tinctoria, the Chilean rhubarb, is a plant species native to southern Chile and neighbour zones in Argentina. It is a large-leaved perennial plant that grows up to two metres tall. It is introduced in large parts of the world as an ornamental and edible plant. In some countries (for instance New Zealand) it has spread from gardens and is becoming a weed problem.
It is known under the synonyms:
Gunnera chilensis Lam.
Gunnera scabra Ruiz & Pav.)
Gunnera tinctoria is a giant, clump-forming herbaceous perennial. The leaves can grow up to 2.5m across. It has erect spikes of cone-shaped inflorescences (to 1m) from spring to early summer, with small flowers. The fruit is orange. The number of seeds is estimated from 80.000 per seedhead to 250.000 per plant.
In parts of New Zealand the Chilean rhubarb has become a recognised pest plant. For instance in Taranaki, on the west coast of the North Island it was spread to riverbeds, coastal cliffs and forest marginssee: Giant problems for Taranaki; especially the pictures of Gunnera tinctoria on seacliffs (p. 17). In New Zealand Gunnera tinctoria, according to the National Pest Plant Accord (NPPA) , is banned. That means: under section 52 and 53 of the Biosecurity Act, it is an offence to knowingly propagate, distribute, spread, sell, offer for sale or display it.
Its large leaves create dense shade, preventing other species from germinating or growing.
The Chilean rhubarb can be controlled by removing the entire plant. Chemical control is advised.
A similar species is Gunnera manicata (the giant rhubarb). This species may also be invasive.
Department of Conservation (NZ) - Plant me instead. Wellington (New Zealand) 2005. ISBN 047814007X
Department of Conservation - leaflet: Chilean Rhubarb; shading out our natives, Wanganui. March 2006.
info on Gunnera tinctoria on the website of Biosecurity NZ.
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article Gunnera tinctoria