General Types of Pond Plants

Plants of ponds and lakes include an incredibly diverse array of types and species. It is not necessary for you to be able to identify all the different species of pond plants. Such identification can be fun but takes considerable training and practice. You may get assistance with species identification from your local office of the Natural Resource Conservation Service, Soil and Water Conservation District or if appropriate you may contact your county Cornell Cooperative Extension Educator for assistance in completing the plant identification form. However it will be useful for you to recognize the general type of your pond plant in order to pick the most appropriate management strategy to address your weed problem.

Pond plants can be broadly organized into five different groups based on their size and whether their leaves and roots occur in the water column, in the air above the water, or in the sediment.

Phytoplankton are microscopic, single-celled algae that float within the water itself. They can not be seen with the unaided eye however in large numbers they will make the water a translucent green, brown or even red color, depending on which species are present.

	Submersed plants are rooted in the sediment but have all of their leaves and stems below the water surface. Examples of submersed plants include both native species, such as eelgrass, and also troublesome exotic species, such as Eurasian milfoil and curly-leafed pondweed. These plants tend to be thin and flexible because it helps them absorb many nutrients directly from the water column. As water levels go up and down, the plants also easily stay submerged.
	Emergent plants are also rooted in the substrate but they have more rigid stems and leaves. This allows them to protrude above the water surface, even as water levels rise and fall. Several common species include the native cattails and bur-reed, but there are also invasive exotic species such as purple loosestrife, giant reed grass and Japanese knotweed.
	Rooted, floating-leafed plants include the attractive water lilies, among others. This group of plants is rooted in the sediment but has flexible stems which allow the large, flat leaves to stay floating on the water surface.
	True, floating plants are not rooted in the substrate. Instead they float on the surface of the water with their roots suspended in the water. They are free to float anywhere on the surface of the lake or pond. This group includes both the tiny, diverse group of 'duckweeds' whose leaves are only a few millimeters in length, and the larger, exotic species, water chestnut and hydrilla.