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Hydrilla

Photo by Robert Vidéki, Doronicum Kft., Bugwood.org

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Common Name: Hydrilla
Scientific Name: Hydrilla verticillata
Origin: Asia

Description

Hydrilla is a submerged perennial that looks similar to american waterweed (Elodea canadensis), a common native aquatic plant. Hydrilla has visibly toothed leaves that grow in whorls of 3-8. Undersides may have one spine, or more, and the mid-rib of each leaf is often reddish. Hydrilla spreads by seeds, tubers, plant fragments and turions (overwintering buds).

Habitat

This plant is tolerant of a wide range of environmental conditions and can be found in lakes, ponds, reservoirs, rivers, canals and drainage ditches. It has low light requirements and thrives in both high and low-nutrient waters.

Threat

Hydrilla spreads rapidly and can completely clog waterways and restrict water flow, posing significant threats to aquatic ecosystems and recreational resources.

Management

A variety of techniques have been used in the United States to manage hydrilla, including mechanical removal, physical habitat manipulation, herbicides and biological agents. Prevention is the most effective control.

Regional Distribution

Early Detection

WNY PRISM Priority

Tier 2 – Eradication

Invasive Species Priorities – Tier Chart

Pathways

Hydrilla was introduced as an aquarium plant. It can sprout from plant fragments and is spread when plant fragments are carried between bodies of water on boats, trailers and other aquatic gear.

Hydrilla is a prohibited species in New York State – for more information on Prohibited and Regulated Species, visit http://www.dec.ny.gov/animals/99141.html.

Native Alternatives 

Southern naiad (Najas guadalupensis)

American elodea/waterweed (Elodea sp.) (E. canadensis, E. nuttallii)

Chara/muskgrass (Chara vulgaris)

Additional Resources

Hydrilla Bibliography

For more information on the Tonawanda Creek/Erie Canal Hydrilla Control Demonstration Project or the Great Lakes Hydrilla Collaborative, visit:  http://hydrillacollaborative.com/