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Giant Rhubarb - Invasive Species Information

Giant Rhubarb - Gunnera tinctoria Biodiversity High Risk

What Is Giant Rhubarb - (Gunnera manicata)?

Habitat: Shade tolerant, prefers damp soil. 
Distribution in Ireland: Western Ireland

Status: Established

Family name: Gunneraceae

Common Name: Brazilian Giant Rhubarb

birds, water and human activity such as the transport and movement of soil containing the seeds.

Reproduction: reproduce by both sexual (seed) and asexual (vegetative) means. Each mature plant is capable of producing up to 250,000 drupe-like seeds every year which are then distributed by

Giant Rubarb size comparison

Giant rhubarb can also regenerate from root fragments, leaf cuttings and rhizomes. Once a small fragment of rhizome becomes established, it can extend by 15cm a year. Please note that breaking the rhizome may result in the creation of more plants.  

Giant Rhubarb Seeds

Giant Rhubarb

Giant rhubarb is a large perennial plant which is native to Chile and Argentina in South America. It was first introduced to Ireland in the 1800s as an ornamental garden plant because of its size and exotic appearance. Since then, it has escaped into the wild and is now particularly invasive along the western coast.  

How To Identify Giant Rhubarb?

Leaf: Very Large Dark Green Leaf 

Seeds: Green/Orange

Size: Can grow to 3 metres high and 4 metres wide

Stem, weak spines on stem and under leaf

Giant Rhubarb is shade tolerant so it may colonise in a variety of landscapes.

 

The dense stands of Giant Rhubarb can render large areas unsuitable for agricultural or amenity purposes.

Giant Rhubarb Gunnera tinctoria ID Guide

Giant Rhubarb - Gunnera manicata ID Guide

The species can invade native grassland and subsequently reduce the value of the land for grazing.

Why Is Giant Rhubarb A Problem?

Giant Rhubarb threatens indigenous biodiversity. Once established, it can quickly develop large and dense colonies which prevent native plants from growing underneath them.

Giant Rhubarb is an invasive species which can seriously effect drainage and water run-off, leading to increase flood risks.

Small fragments of plant material may be spread unintentionally on shoes and clothes.

As the plant is capable of regeneration from small pieces of rhizome, all material must be handled and disposed of in a way which does not result in the potential for further spread.

 

Management, Control and eradication requires continued input and follow-up over a number of years to deal with re-growth and subsequent seedling germination.

Giant Rhubarb - Gunnera tinctoria Riverside

Giant Rhubarb Leaves

It is recommended that any attempt to control Giant Rhubarb should be carried out by trained and experienced personnel.

European Communities (Birds and Natural Habitats) Regulations 2011 non-native invasive plant species A-Z (Updated 2017)

There are currently 35 invasive plant species listed in the European Communities (Birds and Natural Habitats) Regulations (annex 2, Part 1)...

 

Click on a species from the following list to find out more regarding non-native species subject to restrictions under Regulations 49 and 50.

  1. American Skunk-CabbageLysichiton americanus

  2. Brazilian Giant-RhubarbGunnera manicata

  3. Broad-Leaved RushJuncus planifolius

  4. Cape PondweedAponogeton distachyos

  5. Cord-GrassesSpartina (all species and hybrids)

  6. Curly Waterweed - Lagarosiphon major

  7. Dwarf Eel-GrassZostera japonica

  8. FanwortCabomba caroliniana

  9. Floating PennywortHydrocotyle ranunculoides

  10. Fringed Water-LilyNymphoides peltata

  11. Giant HogweedHeracleum mantegazzianum

  12. Giant KnotweedFallopia sachalinensis

  13. Giant-RhubarbGunnera tinctoria

  14. Giant SalviniaSalvinia molesta

  15. Himalayan BalsamImpatiens glandulifera

  16. Himalayan KnotweedPersicaria wallichii

  17. Hottentot-FigCarpobrotus edulis

  18. Japanese KnotweedFallopia japonica

  19. Large-Flowered WaterweedEgeria densa

  20. Mile-a-Minute WeedPersicaria perfoliata

  21. New Zealand PigmyweedCrassula helmsii

  22. Parrots FeatherMyriophyllum aquaticum

  23. Red AlgaGrateloupia doryphora

  24. RhododendronRhododendron ponticum

  25. SalmonberryRubus spectabilis

  26. Sea-Buckthorn Hippophae rhamnoides

  27. Spanish Bluebell Hyacinthoides hispanica

  28. Three-Cornered LeekAllium triquetrum

  29. WakameUndaria pinnatifida

  30. Water ChestnutTrapa natans

  31. Water FernAzolla filiculoides

  32. Water LettucePistia stratiotes

  33. Water-PrimroseLudwigia (all species)

  34. WaterweedsElodea (all species)

  35. WireweedSargassum muticum

Additional Non-Native Plant Species identified as Medium Risk on Ireland's Biodiversity List...

Common name 

African woodsorrel

American skunk cabbage

Annual bur-sage

Antithamnionella ternifolia

Barberry

Black currant

Brazilian waterweed

Butterfly-bush

Canadian-fleabane

Clover broomrape

Creeping Bellflower

Dead man's fingers

Douglas fir

Early goldenrod

False acacia

Field penny-cress

Garden lupin

Giant rhubarb

Hairy rocket

Himalayan honeysuckle

Himalayan knotweed

Holm oak

Japanese barberry

Japanese honeysuckle

Japanese rose

Leafy spurge

Least duckweed

Narrow-leaved ragwort

New Zealand bur

Ostrich fern

Pampas grass

Pitcherplant

Red oak

Red sheath tunicate

Rock cotoneaster

Rum cherry

Russian-vine

Salmonberry

Sea-buckthorn

Sycamore

Three-cornered garlic

Traveler's-joy

Tree of heaven

Turkey oak

Virginia-creeper

Warty cabbage

Water fern

Wild parsnip

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