Reproduction: The plant spreads by the rosettes and fruits detaching from the stem and floating to another area on currents or by fruits clinging to objects, and animals.
Water Chestnut Leaves
The species are floating annual aquatic plants, growing in slow-moving water up to 5 m deep, native to warm temperate parts of Eurasia and Africa. They bear ornately shaped fruits, which resemble the head of a bull or the silhouette of a flying bat. Each fruit contains a single very large, starchy seed.
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This plant should not be confused with the unrelated Eleocharis dulcis, also called a water chestnut. Eleocharis is also an aquatic plant raised for food since ancient times in China. Eleocharis dulcis is a sedge, whose round, crisp-fleshed corms are common in Western-style Chinese food.
How To Identify Water Chestnut?
Leaf: Dark green serrated leaves
Fruit: "Bat-shaped" fruit
Water Chestnut - Trapa natans ID Guide
Water Chestnut Clean-up Operation
Why Is Water Chestnut A Problem?
Fasciolopsiasis is an ailment resulting from infection by the trematode Fasciolopsis buski, an intestinal fluke of humans, endemic in China, Taiwan, Southeast Asia, Indonesia, Malaysia, and India; this fluke can be transmitted via the surfaces of these and other water plants.
During the metacercarial stage in their lifecycle, the larval flukes leave their water snail hosts, and swim away to form cysts on the surfaces of water plants, including the leaves and fruit of water caltrops. If infected water plants are consumed raw or undercooked, the flukes can infect pigs, humans, and other animals.
Water Chestnut - Invasive Species Information
What Is Water Chestnut - (Trapa natans)?
Habitat: Aquatic
Distribution in Ireland: Inland lakes, ponds and canals, abundant in some places.
Status: Established
Family name: Lythraceae
European Communities (Birds and Natural Habitats) Regulations 2011 non-native invasive plant species A-Z (Updated 2017)
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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.
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American Skunk-Cabbage - Lysichiton americanus
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Brazilian Giant-Rhubarb - Gunnera manicata
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Broad-Leaved Rush - Juncus planifolius
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Cape Pondweed - Aponogeton distachyos
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Cord-Grasses - Spartina (all species and hybrids)
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Curly Waterweed - Lagarosiphon major
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Dwarf Eel-Grass - Zostera japonica
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Fanwort - Cabomba caroliniana
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Floating Pennywort - Hydrocotyle ranunculoides
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Fringed Water-Lily - Nymphoides peltata
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Giant Hogweed - Heracleum mantegazzianum
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Giant Knotweed - Fallopia sachalinensis
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Giant-Rhubarb - Gunnera tinctoria
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Giant Salvinia - Salvinia molesta
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Himalayan Balsam - Impatiens glandulifera
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Himalayan Knotweed - Persicaria wallichii
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Hottentot-Fig - Carpobrotus edulis
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Japanese Knotweed - Fallopia japonica
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Large-Flowered Waterweed - Egeria densa
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Mile-a-Minute Weed - Persicaria perfoliata
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New Zealand Pigmyweed - Crassula helmsii
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Parrots Feather - Myriophyllum aquaticum
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Red Alga - Grateloupia doryphora
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Rhododendron - Rhododendron ponticum
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Salmonberry - Rubus spectabilis
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Sea-Buckthorn - Hippophae rhamnoides
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Spanish Bluebell - Hyacinthoides hispanica
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Three-Cornered Leek - Allium triquetrum
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Wakame - Undaria pinnatifida
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Water Chestnut - Trapa natans
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Water Fern - Azolla filiculoides
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Water Lettuce - Pistia stratiotes
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Water-Primrose - Ludwigia (all species)
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Waterweeds - Elodea (all species)
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Wireweed - Sargassum muticum