Maine Field Guide to Invasive Aquatic Plants - Brant Lake Milfoil ...

U s i n g t h e F i e l d G u i d e
B A C K G R O U N D
The primary purpose of this guide is to help users recognize the eleven
invasive aquatic plants on Maine’s invasive aquatic plant list, and to
distinguish these invaders from their more common native look alikes.
One does not need to have previous knowledge of aquatic plants to
use this guide, or, for that matter, to successfully detect a suspicious
aquatic plant. Indeed, most of the aquatic plant infestations known to
date in Maine have been detected by those with limited experience in
plant identification.
Though familiarity with the native plants is not a prerequisite for
successfully screening waterbodies for invasive plants, it does provide
some advantages. The more familiar one becomes with the plants that
belong in a particular waterbody, the greater the likelihood that one
will notice an “outsider” if and when it does appear. It is not unusual
for one’s familiarity with Maine’s native aquatic plants to increase
naturally during the survey process. This guide offers a starting point
in this regard, providing useful information regarding some of the
more common native plant species found in Maine waters.
Generally, only common native plants that share one or more notable
characteristics with one of the eleven listed invaders are included in
this guide. Less common species have been included only in cases
where the rarer species is a very close look alike to one of the listed
invaders. Recommendations for additional native plant identification
resources are provided in the Sources section.
For those with some familiarity with aquatic plants, many of the more
common plant species can be easily ruled out as being suspicious by
observing them from a boat, using a viewing scope as needed.
However, when one is starting out in unfamiliar territory, it is a good
idea to plan on collecting representative specimens from suspicious or
unknown plants for later, more-detailed observation. For some plant
species, accurate identification is virtually impossible (even for the
seasoned expert) without collecting specimens for closer scrutiny.
Tips For Using This Field Guide
1. Read through the Background section, especially the material on
plant structure. If you have recently participated in Invasive Plant
Patrol (or equivalent) training, a quick review of this section should be
sufficient.
2. Use the simplified key provided on page 12 to determine a possible
identification for the plant in question. Turn to the page(s) indicated,
and compare your specimen to the featured plant(s). Also check your
specimen against all of the look alike plants listed for each featured
species. Plant names shown in colored fonts, where used, indicate
native or invasive status: red indicates an invasive plant species and
green indicates native plant species.
Maine Volunteer Lake Monitoring Program