Cattails are probably the most familiar of all wetland plants. Their distinctive cluster of tiny brown flowers can be seen at the edges of ponds, rivers, lakes or just about any other place where there is shallow, standing water for at least a portion of the year.
This distinctive plant can grow up to nine feet in height. A species found in south Delaware will often grow to as much as twelve feet in height. The real key to their survival seems to be its capacity to withstand saturated soil conditions.
Water chestnut can grow in any freshwater setting, from intertidal waters to 12 feet deep, although it prefers nutrient-rich lakes and rivers. Presently, the plant is found in Maryland, Massachusetts, New York and Pennsylvania, with most problematic populations occurring in the Connecticut River valley, Lake Champlain region, Hudson River, Potomac River and the upper Delaware River.
Water chestnut can form dense floating mats, severely limiting light -- a critical element of aquatic ecosystems. This plant can also reduce oxygen levels, which may increase the potential for fish kills. It competes with native vegetation and is of little value to waterfowl.
Water chestnut infestations limit boating, fishing, swimming and other recreational activities. Further, its sharp fruits, if stepped on, can cause painful wounds. Water chestnut has been declared a noxious weed in Arizona, Massachusetts, North Carolina and South Carolina. Its sale is prohibited in most southern states.
Curly leaf pondweed is an invasive plant that forms surface mats that interfere with aquatic recreation. The plant usually drops to the lake bottom by early July.
Milfoil is an aggressive, non-native water weed which is now spreading throughout the United States. This weed chokes out native plants and spreads rapidly to new areas. Milfoil reproduces by a process called fragmentation. Milfoil plants break easily into small pieces and each piece can form roots. A single wisp can multiply into 250 million new plants in one year. Milfoil is readily spread between lakes and rivers by boaters carrying plant fragments on their boats and trailers.
Active prevention of milfoil invasions should involve various approaches. Public awareness of the necessity to remove weed fragment at boat landings, a commitment to protect native plant beds from speed boaters and indiscriminate plant control that disturbs these beds, and a watershed management program to keep nutrients from reaching lakes and stimulating milfoil colonies.
Monitoring and prevention are the most important steps for keeping Eurasian water milfoil under control. A sound precautionary measure is to check all equipment used in infested waters and remove all aquatic vegetation upon leaving the lake or river. All equipment, including boats, motors, trailers and fishing/diving equipment, should be free of aquatic plants.
Lake managers and lakeshore owners should check for new colonies and control them before they spread. The plants can be hand pulled or raked. It is imperative that all fragments be removed from the water and the shore. Plant fragments can be used in upland areas as a garden mulch.
This floating rosette with its showy purple flower, propagates vegetatively by daughter plant production. Most commonly found in the Gulf coast states, Florida, Georgia, South Carolina, and the Sacremento River Delta in California.
A member of the Pontederiaceae (Pickerelweed) family can often be found in a floating mat or rooted in moist soil. Waterhyacinth is the most important nuisance aquatic plant worldwide, and in the US, Florida spends approximately $5 million per year because of it and its major negative impact on aquatic ecosystems.
A major nuisance species in tropical and subtropical regions, Araceae mainly appears as a floating rosette species, with leaves having dense hairs and inconspicuous flowers. Water Lettuce may also be found rooted in moist soil coastally from Florida to Texas.
Pontederiaceae, more commonly known as Pickerel Weed is a stout emergent with heart-shaped leaves growing from an enlarged base, it has a showy purple flower spike formed by numerous seeds. This perennial is commonly found in shallow waters with moist soil habitats in Eastern North America.
Scientifically know as Nuphar Polysepala and more commonly known as yellow pond or cow lily. This rooted, floating-leaved plant with bright yellow ball-like flowers are often confused with the fragrant water lily (Nymphaea odorata), a similar looking exotic plant that has showy white, sometimes pink, many-petaled and fragrant flower.
In the early spring the spatterdock's leaves are below the surface, light green in color, and look like lettuce growing on the lake bottom. By late spring the broad, dark green, heart-shaped leaves float on the water's surface or often stand above the water as the summer progresses. The bright yellow flowers bloom from June to mid-August and also stand just above the water surface. The flower emits a strong brandy-like odor which attracts pollinating insects. Spatterdock reproduces by seeds and spreads by growth of its large fleshy roots which can be up to six inches in diameter and many feet long. It has also been known to reproduce from fragments of roots if the plant is broken up.
It is commonly referred to as "that aquarium plant" or Canadian waterweed, hydrilla or elodea. The plant has leaves in whorls. The American variety has three leaves per whorl, other varieties usually have more than 3 leaves per whorl and can be larger and bushier plants. American waterweed lives entirely underwater except for small white flowers that bloom at the surface and are attached by delicate stalks to the rest of the plant. In the fall, stalks of the plant break off and float away, root and start new plants.
Silty sediments and nutrient rich water promote the growth of this waterweed. Other than being considered a nuisance, the American Waterweed is an important part of lake ecosystems. It offers cover for young fish and amphibians. Waterfowl, beaver and muskrat eat this plant. It is also used ornamentally in aquariums.