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 invaded field showing fully expanded leaves