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Cape Pondweed - Invasive Species Information

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What Is Cape Pondweed - (Aponogeton distachyos)?

Habitat: Slow Moving Water, Lakes and Ponds
Distribution in Ireland: Limited wetland areas

Status: Established

Family name: Aponogetonaceae

Reproduction: Seeds prolifically. Spreads by seeds and tubers. Seeds are dispersed by water and waterfowl. 

Cape Pondweed,  also known as water hawthorn, is an aquatic plant growing from a tuberous rhizome.

Cape Pondweed - Aponogeton distachyos Infestation

Cape Pondweed - Aponogeton distachyos Leaves & Flowers

Cape pondweed has a basal globose tuber, 3-4 cm in diameter. Floating leaves are basal, dark green, up to 25 cm long, narrow-lanceolate in shape, and with many distinctive cross veins. Submerged leaves are linear in shape. Flowers are on a two- forked spike with fleshy white lobes and very fragrant. 

The often mottled leaves float on the water surface from a petiole up to 1 m long from the rhizome;

How To Identify Cape Pondweed?

Leaf: Light Green Leaf the leaf blade is narrow oval, 6–25 cm long and 1.5–7.7 cm broad, with an entire margin and parallel veins.


Flower: White Flower with pale yellow stamen


Size: Can grow almost indefinitely in slow moving water pools 

Cape Pondweed - Aponogeton distachyos - ID Guide

Cape Pondweed - Aponogeton distachyos ID Guide

Cape Pondweed Flower
Cape Pondweed Roots
Cape Pondweed Infestation

Cape Pondweed - Aponogeton distachyos Flower, Roots and Leaves

Why Is Cape Pondweed A Problem?

Infestations can provide breeding grounds for mosquitos. Impacts could occur in waters such as slow flowing freshwater streams and rivers, and in lakes and ponds.

Can form mats on the water surface which can block waterways and contribute to flooding. 

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

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