# Water caltrop (*Trapa natans*) Water caltrop is a unique plant that grows in water. It has interesting, nut-like fruits that look like little horns. These fruits float on the water's surface and can be fun to spot! - **Category:** [Plants](https://www.snappit.app/explore/categories/plant) - **Rarity:** Common - **Danger:** 2/5 · Low - **Snaps:** 2 - **Habitat:** Wetlands ![Water caltrop](https://commons.wikimedia.org/w/index.php?title=Special:Redirect/file/Expedition_10.jpg&width=800) Photo: Bilous Olena, CC BY 4.0 · [Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Expedition_10.jpg) ## Appearance The Water caltrop has distinctive triangular, serrated leaves that form a dense, floating rosette on the water's surface. Its unique, four-horned, woody fruit is dark brown to black and looks somewhat like a bat's head. Small, white flowers emerge from the leaf axils. ## Taxonomy - **Kingdom:** Plantae - **Phylum:** Tracheophyta - **Class:** Magnoliopsida - **Order:** Myrtales - **Family:** Lythraceae - **Genus:** Trapa ## Interesting facts - Ancient people in Europe gathered Water caltrop fruits as a food source! - Its bizarre, horned fruit is sometimes called a 'devil pod' or 'bat nut'! - The spiky seeds can stay viable underwater for more than twelve years! - This plant can remove excess nutrients, helping to clean pond water! ## Special abilities - **Floating Sun Collectors:** Water caltrop has buoyant, air-filled leaf stalks that keep its diamond-shaped leaves afloat, ensuring they capture maximum sunlight. - **Armored Seed Pods:** Water caltrop produces incredibly tough, spiky fruits that sink to the bottom, protecting its seeds until they can sprout next season. - **Deep Anchors:** Water caltrop can extend long, submerged stems to anchor itself in water depths up to five meters, helping it survive varying conditions. ## Measurements & details - **Height:** 30-500 cm - **Spread:** 15-30 cm - **Flower Size:** 0.8-1 cm - **Bloom Season:** Summer - **Edible:** Yes - **Toxicity:** None - **Lifecycle:** Annual - **Pollination Method:** Self ## Ecological connections - **Eaten by:** Mallard duck (*Anas platyrhynchos*) — Ducks eat the floating seeds and leaves. - **Eaten by:** [Common carp](https://www.snappit.app/explore/common-carp) (*Cyprinus carpio*) — Fish graze on submerged stems and associated organisms. - **Shelter:** [Yellow Perch](https://www.snappit.app/explore/yellow-perch) (*Perca flavescens*) — Young fish find protection within its dense leaf mats. ## Traits - [Ornamental](https://www.snappit.app/explore/traits/ornamental): Ornamental plants are cultivated primarily for their aesthetic appeal, enhancing landscapes and gardens with their attractive foliage, flowers, or form. - [Fruit Bearing](https://www.snappit.app/explore/traits/fruit-bearing): Fruit-bearing plants produce fruits, which are the mature ovaries of flowering plants containing seeds. - [Nut Bearing](https://www.snappit.app/explore/traits/nut-bearing): Nut bearing plants produce hard-shelled fruits, commonly known as nuts, which contain a single seed and are a valuable food source. - [Edible](https://www.snappit.app/explore/traits/edible): Edible plants are those parts of a plant that are considered safe for human consumption. - [Wetland](https://www.snappit.app/explore/traits/wetland): This habitat trait identifies species found in wetlands, which are areas of land saturated with water, either permanently or seasonally, including marshes, swamps, and bogs. - [Freshwater](https://www.snappit.app/explore/traits/freshwater): Freshwater habitats include non-saline aquatic environments such as rivers, lakes, ponds, and wetlands, vital for numerous species. - [Keystone Species](https://www.snappit.app/explore/traits/keystone-species): Describes a species whose presence and role have a disproportionately large effect on its environment. - [Aquatic](https://www.snappit.app/explore/traits/aquatic): Aquatic habitats encompass environments where organisms live predominantly in water, including oceans, rivers, lakes, and wetlands. ## Collections - [Plants](https://www.snappit.app/explore/collections/plants) ## Safety **Danger:** 2/5 · Low Always be careful around water plants and don't touch anything sharp. ## Frequently Asked Questions ### How to identify Water caltrop? Start with the whole plant, then compare leaf arrangement, leaf edges, stems and any flowers or fruit. Opposite leaves grow in pairs; alternate leaves come one at a time along the stem. These details tell you far more together than a single green leaf does. Plant Identifier: upload a photo and compare the visible details. ### How tall is Water caltrop? 30-500 cm ### How wide does Water caltrop spread? 15-30 cm ### How big are the flowers on Water caltrop? 0.8-1 cm ### When does Water caltrop bloom? Summer ### Is Water caltrop edible? Yes ### Is Water caltrop toxic? None ### What is Water caltrop's lifecycle? Annual ## Where to spot - [Camp Evans](https://www.snappit.app/guides/places/camp-evans) — New Jersey, US · Historic Site - [Arrowhead Park](https://www.snappit.app/guides/places/arrowhead-park) — Virginia, US · Park - [King Phillip's Cave](https://www.snappit.app/guides/places/king-phillips-cave) — Massachusetts, US · Natural Landmark - [Newburgh Colored Burial Ground](https://www.snappit.app/guides/places/newburgh-colored-burial-ground) — New York, US · Historic District - [Rhinebeck Village Historic District](https://www.snappit.app/guides/places/rhinebeck-village-historic-district) — New York, US · Historic District [View all places to see Water caltrop](https://www.snappit.app/guides/where-to-see/water-caltrop) ## More Plants - [white snakeroot](https://www.snappit.app/explore/white-snakeroot) (*Ageratina altissima*) - [tree-of-heaven](https://www.snappit.app/explore/tree-of-heaven) (*Ailanthus altissima*) - [western sword fern](https://www.snappit.app/explore/western-sword-fern) (*Polystichum munitum*) - [common milkweed](https://www.snappit.app/explore/common-milkweed) (*Asclepias syriaca*) --- Source: [Water caltrop: Facts & Places to See — Snappit](https://www.snappit.app/explore/water-caltrop)