Waterwheel has small, clamshell-type traps to capture prey. Photo by Shaun Winterton, Aquarium and Pond Plants of the World, Edition 3, USDA APHIS PPQ, Bugwood.org
SCIENTIFIC NAME:Aldrovanda vesiculosa
ORIGIN:Africa, Australia and Eurasia
DESCRIPTION:Waterwheel is an herbaceous carnivorous, aquatic plant that captures small, aquatic invertebrates using clamshell-type traps, similar to the venus flytrap. It floats just below the water's surface and has stems 2-8 inches long, with whorls of 5-9 leaves. Waterwheel rarely flowers, but when it does, the small, greenish-white flowers emerge from the water, while the fruit capsules are held underwater.
HABITAT:Waterwheel invades human made, and disturbed, wetland habitats, and pools of acidic and tannic water. In optimal conditions, it can double its mass in 13 days and grow one new whorl of carnivorous leaves per day.
THREAT:Each plant has up to 200 traps and 80% may contain prey at any given time. This predation interrupts food webs and harms invertebrate populations. The prolific growth of waterwheel clogs water systems, damaging infrastructure and interrupting recreational activities.
Clean, drain, dry prevention methods are ideally suited to stop the spread of this species. Manual removal efforts have had little impact on waterwheel populations and more research is required to determine the Best Management Practices for this species.
WNY PRISM PRIORITY:
Tier 1 - Raise Awareness
NYS Invasive Species Tiers Chart - Tier Definitions
NYS Prohibited and Regulated Species - Part 575:
PATHWAYS OF INVASION:
This plant was intentionally introduced to North America as a means to save it from extinction in its native range. Waterwheel can spread by seeds, turions, and through the transportation of leaf material. Turions are clusters of modified leaves that overwinter on the bottom of the wetland and can create an entire new plant in the spring.
Within NYS, waterwheel is only found within the Catskill PRISM region.