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Invasive Species: Hydrilla

Invasive Species: Hydrilla

Hydrilla

(Hydrilla verticillata)
*Not detected in Michigan*

WATCH LIST - PROHIBITED IN MICHIGAN

Report this species to:

EGLE Aquatic Invasive Species Program EGLE-WRD-AIP@Michigan.gov.

If possible, please take one or more photos of the invasive species you are reporting. Also make note of the location, date and time of the observation. This will aid in verification of your report. You may be asked to provide your name and contact information if follow-up is needed.

- Or - use the Midwest Invasive Species Information Network (MISIN) online reporting tool

- Or -  download the MISIN smartphone app and report from your phone - MISIN.MSU.edu/tools/apps/#home

Identification:

  • Submerged aquatic plant with generally green leaves.
  • Leaves are whorled in group of 4-8.
  • Leaf mid-vein is reddish with a row of spines giving it a rough texture.
  • Very slender stems that can grow up to 30 feet long.
  • Stems branch out considerably near water surface.
  • White 3-petaled flowers (may be reddish or brown on male plants).
  • Easily confused with Brazilian elodea (another invasive) – hydrilla leaves are rough and have visible saw-toothed margins.

hydrilla
Photo courtesy of Robert Videki, Doronicum Kft., Bugwood.org.

hydrilla in water
Photo courtesy of David J. Moorhead, University of Georgia, Bugwood.org.

hydrilla photo
Photo courtesy of Robert Videki, Doronicum Kft., Bugwood.org.

Habitat: This herbaceous, perennial aquatic plant can grow in springs, lakes, ditches, marshes or rivers. It can tolerate a variety of nutrient conditions and has the ability to grow in low light conditions, giving it an advantage over native species.

Native Range: Central Africa.

U.S. Distribution: Hydrilla has been recorded throughout the southern U.S. from California to Delaware.

Local Concern: Hydrilla is a threat to native aquatic ecosystems. Dense mats shade out native aquatic vegetation and alter the ecology of the water body. Invasion also interferes with recreational activities like boating and fishing.

Other Common Names: Florida elodea, Wasserquirl, Indian star-vine, water thyme.

MORE INFORMATION:

Hydrilla Invasive Species Alert - Printable PDF