Aquatic Plants: Submergent, Emergent, Floating-leaf and Free-floating

What is the difference between emergent, submergent and other aquatic vegetation?

Emergent Plants:

emerge or have a large portion of their shoots, leaves or flowering structures out of the water.  These include the familiar cattails, and also bulrushes, wild rice, sedges, bur-reed and many others.  Emergent vegetation can refer to any wetland plant that is above the water, however for the purposes of the this website I will categorize a plant as emergent only if is frequently aquatic in habit.

Wool Grass

A tuff of Wood Grass growing high above the other vegetation of this sedge meadow.

Submergent Plants:

plants that have most of their structures below water.  Common examples of these would be coontail, milfoils, and many pondweeds.

Submergent Plants

A mass of submergent aquatic plants: Coontail, Common Waterweed, Pondweeds, and even some Chara algae

Floating-leaf Plants:

have floating leaves.  They include the water-lilies, some pondweeds, and American lotus, although the latter often protrude from the water.

Floating Leaf Water Shield

In the center is the flower of the Water-shield (Brasenia schreberi) an aquatic floating-leaf plant.

Free-floating Plants:

these non-rooted plants include the duckweeds, common bladderwort and often coontail.  Coontail is sometimes rooted, but it is dislodged easily by wave action and will continue growing in a floating mass, or tangled in with other plants.

Duckweed

Lesser Duckweed (Lemna minor) is a free-floating aquatic plant often mistaken for algae, but it is in fact a flowering plant.

 Mixed Type:

Some plants have a mixture of different stages of growth.  As mentioned above, American Lotus can be a floating-leaf plant, or the leaf can emerge from the water on its stems.  Some pondweeds have both underwater (submergent) leaves, and floating leaves.  Coontail, which is one of our most common aquatic plants, is often not rooted and drifts around, getting caught in other vegetation.  These differences can be somewhat confusing, and most often these species with “in between” growth patterns are simply labeled one or the other.

Note:  Most often freshwater aquatic plants are simply refereed to as weeds or even seaweed.  This is unfortunate as a weed is very negative term.  Aquatic plants are extremely important to lake health.  In science we often call aquatic plants, aquatic macrophotyes to include some of the macro algae like chara and nittella.