Wetlands, as their name implies, are wet and develop along the edges of rivers, streams, lakes, or other aquatic areas. They either have standing water or the soil is saturated with water during some part of the growing season. Wetlands vary, depending on the type of soil, whether it's flat or moving water, climate, and the types of vegetation that grow there. Near the coast there are tidal marshes and swamps that may be either fresh or salt, depending on how far they are from the sea. Plants that grow in these marshes have to adapt to fluctuating water levels that range from completely drying out to being totally submerged. Not a lot of plants can grow in salt marshes. Those that grow there have special adaptations that enable them to survive. There are also nontidal wetlands that can be found in low areas anywhere from the coast to the mountains. These wetlands generally have a greater diversity of plant life.
Swamps are wetland areas that border creeks, bays, and waterways and are found throughout the United States. They are characterized by trees that have adapted to wet conditions. Bald cypress and water tupelo trees are able to grow in standing water and are common in the southeast. Wide buttresses add support and stability to the trees. Cypress knees emerge above the water surrounding cypress trees, also helping to stabilize them.
As plants accumulate in the knees and break down into soil, a micro-habitat is formed as seedlings emerge from seeds that have germinated in the soil.
In the spring and summer, a number of flowering plants add color to the swamps. This includes sundrops, irises, wild roses, and several species of lobelias. These plants provide nectar for pollinating insects. Other plants produce fruits that are edible, including the fruits of wild roses, known as “hips,” that are especially versatile, and can be used both as a food and to make a mild-flavored tea. Blueberries, serviceberries, viburnums, and chokeberries also produce edible fruits.
Layers of peat, which is partially decomposed organic material, mainly dead leaves and other plant material, characterize bogs. Long, cold winters, short cool summers, sufficient moisture, and trees with acidic litter are vital for peat formation. Once they are established, the acidity of the bog slows down the decomposition of added plant material and they continue to grow, providing a unique wetland habitat.
Cranberries grow in bogs and are in the heath family, along with blueberries and huckleberries. There are three species native to the United States. The large cranberry is the same species that is cultivated and sold in grocery stores around Thanksgiving time, but it also grows wild in boggy areas.
Riparian habitats develop along the banks of freshwater creeks, streams, and rivers that are prone to flooding. Land is moved as new streams are dug out by moving water. Plants that grow here have adapted to these changing conditions. Spicebush, sweet birch, river birch, and black willow are sometimes seen growing on these banks. In addition to stabilizing the banks, they also filter pollutants from the water and provide habitat for wildlife.
Marshes are wetland areas that develop along the edges of bays, rivers, or canals. They are characterized by grasses and grasslike plants, including sedges, rushes, and cattails. There are both freshwater marshes and saltwater marshes. In some areas there are freshwater tidal marshes, where the waterway is beyond the reach of salt but is still influenced by the tide. There are also saltwater marshes whose water level is influenced by the wind rather than the moon.
Marshes have historically been referred to as wastelands and not good for anything but to breed mosquitoes. However, marshes are a very productive ecosystem. Not only do they provide food for wildlife, but they also offer an abundance of food for humans, as long as they know where to look.
There are some wildflowers in the marsh that are edible. The large showy flowers of several species of mallow, the most easily recognized marsh flower, as well as the purplish spike of flowers of the pickerelweed are both edible, as are the fruits. Bacopa forms a mat on some marshes and has succulent, edible leaves. It blooms all summer with small, white flowers.
The water level of freshwater marshes is generally influenced by the amount of rainfall and is a more stable environment than the fluctuating water levels of salt marshes. As a result, there is a greater diversity of plants in freshwater marshes. Cattails, arrowheads, groundnuts, and pickerelweed all grow in freshwater marshes.
Along the banks of streams, creeks, and rivers is a low-growing herb known as pennywort. There are a number of different species scattered across most of the country. It is in the carrot family and has small, white-topped clusters of flowers that appear during the summer. The most distinctive feature is the leaf, which is round and has the leaf stalk coming out of the center for some species. Pennywort is related to gotu kola that is sold in health food stores. The leaves are edible, but bitter.
There are a number of roots that can be harvested from freshwater marshes. These are generally deeply embedded in the mucky soil, making removal a difficult and somewhat messy procedure! A digging fork or any similar instrument works best to pry them loose from the mud. Some of the roots that can be harvested in a marsh include those from the easily recognizable cattails, arrowheads (discussed in detail later in the book), and water lilies. Groundnuts also grow along the banks in somewhat sunny areas. Their roots grow just beneath the surface of the soil in long strings, making them easy to harvest.
Mucky soil, which is partially decomposed plant material, characterizes marshes. The muck is like a giant sponge that slowly absorbs and releases water. When you step on a sponge it compresses and then expands when you lift your foot off. If you find yourself stuck in the muck, drop to your knees or all fours to center your weight and free yourself.
Salt marshes develop around bays or estuaries that have an opening to the sea. The plants that grow here have to adapt to the salt water as well as the fluctuating water level. Some plants, like the black needlerush, store the salt in their tips. Saltmarsh cordgrass excretes the salt onto the surface of their leaves. Salicornia and orache dilute the salt in their stems.