Emergent aquatic plants grow in shallow areas, usually along the banks of ponds or lakes, or in shallow marshy areas. Some may not be considered aquatic vegetation, but can survive in wet soils for an extended period of time. Emergent plants, unlike submerged vegetation, are rigid and can stand on their own, without support from the water.
These again, can be desirable or undesirable depending on balance and what you like to see. Often times, emergent vegetation can be very beneficial as a nutrient buffer. They can block or at least slow down nutrients that are entering the pond due to runoff. Emergent vegetation also serves to stabilize the shoreline and reduce erosion. Deep rooted vegetation keeps the shoreline intact. Desirable varieties also provide wildlife food and habitat. Below are some common submerged aquatic plants and some information about them. This section of the page is an ongoing process, so check back for more additions.
Pickerel Rush (Pontederia cordata) is a plant that is often sold in watergarden stores that sell aquatic plants. It produces a nice purple flower and is great for the banks of ponds and watergardens. It will use up and block some of the runoff nutrients entering the pond and look good doing it.
Cattails (Typha spp.) are probably the most recognizable plant in and around water. The tall stalks or stems with long, green leaves are very recognizable and the 6-8" brown cylindrical spike produces seeds for reproduction. Cattails can spread quickly if not controlled. Cattails serve as cover for wildlife and also as a food source for aquatic rodents, such as Muskrats.
Arrowhead (Syngonium spp.) is named after the "arrowhead" shaped leaves. There are several species within the arrowhead family. The white flowers are in whorls of 3 with a yellow center. Arrowhead is a good plant to use up nutrients, but need to be kept in check to prevent over population.
Bog Moss (Mayaca fluviatilis) is typically found in wetlands or wet areas around ponds in creeping mats. It is a small, dark green, branched plant with leaves spirally arranged on the stem. Small pick flowers are produced with 3 petals. It can serve to block runoff nutrients from entering the water.
Water Primrose (Ludwigia spp.) can be emergent or submersed plants, depending on the species. It produces stems that grow horizontally with roots that are wiry. Leaves are produced and alternate along the stems. Erect stems occur during the flowering stage and most typically bloom from April to September, depending on species and location. Water primroses are typically considered desirable aquatic plants.
Spikerushes (Eleocharis spp.) cover a wide range of species. Most grow in moist soil or shallow ponds, marshes, and wetlands. The stems are topped by a terminal spike. Spikerushes can cover many acres and serve as cover for certain wildlife. Certain species of spikerushes are used as a food source for birds and animals, as well as for human consumption.
These pages are reprinted from www.gotalgae.com, courtesy of www.kascomarine.com