Himalayan Balsam

Non-Native Plants

Non-native plant species are frequently found along river corridors in urban areas. This reflects the numerous potential sources of these species in urban areas, including domestic gardens, public parks, road and rail verges, abandoned land, and golf courses, and also the ability of rivers to collect, disperse and deposit seeds during spates.

Numerous non-native plant species may be present in the vegetation and soil seed bank, and a few of these can become invasive to the extent that they cause significant problems for native vegetation. The Environment Agency recently identified seven non-native plant species that have caused serious problems within rivers and along river banks across Britain: Himalayan balsam (Impatiens glandulifera), Japanese knotweed (Fallopia japonica), Giant Hogweed (Heracleum mantegazzianum), Floating pennywort (Hydrocotyle ranunculoides), Australian swamp stonecrop (Crassula helmsii), Parrot’s feather ((Myriophyllum aquaticum), Creeping water primrose (Ludwigia grandiflora).

American Skunk Cabbage (Lysichiton Americanus)

More info: DEFRA, Nature Locator

Buddleia (Buddleja Davidii)

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Cabbage-palm (Cordyline Australis)

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Canadian Fleabane (Conyza Canadensis)

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Cape Goosberry (Physalis Peruviana)

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Confused Michaelmas-Daisy (Aster Novi-Belgii)

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Fig (Ficus Carica)

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Floating Pennywort (Hydrocotyle Ranunculoides)

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Foxglove Tree (Paulownia Tomentosa)

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Giant Hogweed (Heracleum Mantegazzianum)

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Giant Rhubarb (Gunnera Tinctoria)

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Himalayan Balsam (Impatiens Glandulifera)

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Hoary Cabbage (Hirschfeldia Incana)

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Italian Alder (Alnus Cordata)

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Ivy-leaved Toadflax (Cymbalaria Muralis)

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Japanese Knotweed (Fallopia Japonica)

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Large Evening Primrose (Oenothera Glazioviana)

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Mexican Fleabane (Erigeron Karvinskianus)

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Monkeyflower (Mimulus Guttatus)

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New Zealand Pigmyweed (Crassula Helmsii)

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Parrot’s Feather (Myriophyllum Aquaticum)

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Rape (Brassica Napus)

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Shaggy Soldier (Galinsoga Quadriradiata)

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Small Balsam (Impatiens Parviflora)

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Snowberry (Symphoricarpos Albus)

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Sweet Pepper (Capsicum Annuum)

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Tomato (lycopersicon Esculentum)

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White Melilot (Melilotus Albus)

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Yellow-flowered Strawberry (Potentilla Indica)

More info: DEFRA