Habitat: coastal cliffs, waterways, roadsides, wet meadows and derelict gardens and fields.
Description: Gunnera tinctoria or giant rhubarb is not related to rhubarb, but as its name implies it is similar in appearance. This is a much larger plant with thorny leaves and stems. This is a large herbaceous plant that forms dense colonies and shades out other plants. This plant is most conspicuous in spring and summer when it can grow up to 2 m tall with large ‘umbrella’ shaped leaves that arise from sturdy stalks or petioles. Gunnera over winters as large buds accumulating on the rhizomes (roots) above the surface, while the leaves die back, exposing these buds.
Origin and Distribution: Native to South America but is now invasive in Europe, North America, New Zealand and Australia.
Impacts: Gunnera reduces the biodiversity value of infested sites. It can lead to the local extinction of some species with the formation of almost monospecific stands of gunnera. Elsewhere, this species has also caused problems by blocking drainage ditches and also access ways for people.
How did it get here? The plant arrived in Ireland as an ornamental plant for gardens.
Where is it found in Ireland? The species is currently considered invasive on the west coast of Ireland, although it is also found on the east coast to date it is not considered invasive. It is considered to be having a significant impact on Achill Island, County Mayo, where is has spread throughout.
- Promote native species and biodiversity - use alternative, native plants
- Know what you are buying/growing and source native Irish seed and plants
- Do not swap plants and cuttings
- Clean plants before adding to ponds (dispose of water away from water courses)
- Follow control advice and watch out for hitchhikers - inspect new imported purchases for invasive pest and pathogens
- Never collect plants from the wild