The Project
The Plant
Why is it invasive?
Control Experiments
Clare Island Project

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The Plant
Last updated: 17th November 2009

Gunnera is a herbaceous (not woody), perennial (lives longer than 2 years) plant. Along the ground grows a rhizome (a horizontal stem) from where the leaves grow from. The leaves start to grow in early spring and die back in late autumn. When the leaves are fully expanded they can grow upto 2 m tall and be 2 m wide. From the rhizome an inflorescence (flower head) is also produced which can be around 1 m long, at the end of summer will produce thousands of small red/orange fruits containing the seed. Gunnera forms a symbiotic relationship (to organisms living together) with the cyanobacteria (Nostoc puctiforme) inside the rhizome, this gives it the amazing ability to obtain nitrogen from the atmosphere, possibly allowing it to grow in nutrient porr soils. It can reproduce from both the seed produced on the flower head each year or by vegetative means, i.e. if fragments of the rhizome get broken off they can send out roots and become a new plant.

Gunnera seedling

Gunnera invaded field showing fully expanded leaves