Ponds

Coontail is a submergent vegetation that does not follow the category rules for the group of plants it belongs in. Coontail is found in quiet ponds, lakes, or slow moving streams; generally it does not have roots and never grows above water, even in flowering. Plant stems may be partially found in bottom sediments, but rarely are roots present.

Creeping waterprimrose looks similar to alligator-weed (Alternantltera philoxeroides) in that both have ovate or lance-shaped leaves. Like alligator-weed, which is found along wet habitats including ponds and hydrated soils, it can be prolific. Common near ditch banks, lakes and ponds, waterprimrose sometimes grows so rapidly it can overtake most of a shallow pond. Unlike alligator-weed, waterprimrose is a native to North America.

Many species of filamentous algae are found throughout Maryland in both fresh and brackish water. The genus most common to the freshwaters is Hydrodictyon, while the most common nuisance filamentous algae found in brackish water is Entermorpha. Better known as waternet, Hydrodictyon is a filamentous type which resembles a net with five- to six-sided cell meshes-these nets are generally in the form of a flat sheet, although in some species they can form a cylindrical pouch. Waternet grows well in small ponds and in swamps; it occurs for the most part in hard water systems and is associated with high pH. Populations can become so dense as to interfere with fishing and swimming. Dense populations can cause oxygen depletion and give rise to offensive odor.

Pickerelweed is a perennial plant with thick, creeping rootstocks, and erect leathery leaves that grow in clusters. The plants are found along the margins of lakes, ponds, and streams in soft muddy bottoms, and can grow in a variety of types of water up to 2-1/2 feet deep. They often grow over 3 feet tall, with leaves almost 5 inches wide at the widest point, and twice as long as wide. When in bloom, the plant has a beautiful flowering spike of purplish to violet flowers.

This workbook describes Chara, a branched muskgrass algae that can be found in fresh and brackish waters. There are approximately thirty-five species of muskgrasses, which include Nitellas and two Tolypellas (not pictured here). Muskgrass is called by this name because when crushed in your hand it has a distinctive ill-smelling musky odor. Usually yellow-green to grayish-green, it often carries calcareous (lime) deposits on the branches which feel gritty or bristly. The short, evenlength branches occur in whorls, 6-16 of them, radiating from each joint or node. The branchlets are never forked in Chara. Generally Chara is found in alkaline or hard waters and can become a nuisance, covering the entire pond bottom. In some areas, it may grow as high as three feet. Dense growths may hinder waterflow and even interfere with fishing.

Pennyworts, especially marsh and water pennywort, are commonly found in Maryland aquatic environments. Marsh pennywort is the more common species. These plants are succulent perennials that are members of the parsley family and native to America. Commonly found rooted in the mud along pond and ditch banks, they can form dense mats that float on the surface. These mats can actually break away from their roots and continue living and growing while free floating. The mats can also support other plants such as smartweeds, beggar-ticks, or alligatorweed. The mats may grow to such a density that they may impede waterflow in drainage canals and ditches, which can affect irrigation. Often, a variety of submersed aquatic plants may be found entangled among the roots. Many species of Hydrocotyle can grow well in either an aquatic or terrestrial habitat. Marsh pennywort can be found in either in the coastal plain or more inland areas of the state. Large populations of marsh pennywort are common during the summer.

Maidencane is one of the unjustly labeled nuisance plants found in Maryland. The misrepresentation comes about because it rapidly covers the margins of lakes or ponds, especially when they are dewatered due to drought or summer drawdowns for irrigation. Once established it can form dense stands that make it difficult to pass through or to fish around. It is also one of the most difficult aquatic grasses to control. However, maidencane is one of the more important plants for fish management. The species provides valuable cover and spawning habitat around its roots in alkaline fresh waters and sandy shorelines throughout Maryland.

Hydrilla is an introduced plant in Maryland and is therefore considered an exotic species. In fact, the plant is not native to the United States and may have been introduced from southeast Asia through the aquarium trade. The plant is a perennial herb with slender, branching stems forming loose, often impenetrable mats. It is extremely competitive with other plants and can grow in water as deep as 36 feet. In Maryland, it was originally detected in 1982, and since has become one of the major aquatic plant species in the tidal freshwater portions of the Potomac River. Because of its tenacity and varied means of reproduction, it has been considered a noxious plant in many states.

Giant cutgrass, also known as water millet or southern wild rice, is often misidentified as wild rice but does not have the value as a food source for wildlife as that of true wild rice. It does, however, provide protectional and nesting cover for many species of birds and other animals. It can be found in shallow water, up to 3 feet deep, along the edges of ponds, streams, and marshes. The plant is usually found in freshwater, but is occasionally found in brackish water marshes.

Bushy pondweeds (Najas spp.) are rooted annual slender plants with branching stems. There are four species of the bushy pondweeds, or naiads as they are otherwise known, in Maryland. These four species include Southern naiad, or the plant most commonly known as bushy pondweed (N. guadalupensis); N. minor which has no common name; Northern naiad (N. flexilis); and slender naiad (N.gracillima), which is rare in Maryland. There is a marine naiad (N. marina), but it has not yet been reported in the state.