How do I determine if a suspicious aquatic plant is an invasive?

The Maine Department of Environmental Protection has a team of experienced professional biologists and water quality specialists who are readily available to assist you in the identification of suspicious aquatic plants. DEP staff also has extensive experience in a variety of treatment, eradication and control strategies for water bodies that suffer from infestations of invasive aquatic plants. For more information on plant identification guidelines or infestation control strategies, call DEP biologist John McPhedran at (207) 287-6110 or e-mail him at

Picture of hydrilla in Pickerel Pond, Limerick.

Two ways exist to identify a suspicious plant:

E-mail a photograph:

  1. Take a digital image of the plant that you've collected. Be sure to use a representative specimen of the plant, with fruit or flowers, if available.
  2. Download the image and e-mail it as an attachment to for identification. In your email be sure to include your name, phone number and waterbody name.

Mail a plant specimen

Often, a photo cannot reveal characteristics necessary to identify a plant. That’s when to send a specimen through the postal system. Here’s how:

  1. Collect a representative specimen of the plant you think is invasive (a piece of the stem with leaves is necessary, also any flowers or fruits if present)
  2. Wrap the collected specimen in a damp paper towel, place it in a sealable plastic bag, and mail in suitable padded envelope or box to Maine DEP Invasive Species Program, 17 State House Station, Augusta ME 04333. Include your name, phone number, name of the waterbody, date of collection and the town in which it is located. Also note on envelope or box, “Plant Sample.”
  3. Mail early in the week so that your sample doesn’t spend the weekend in the post office. Maine DEP staff will identify the plant and notify you of its identification usually within 48 hours of receipt.