What are some examples of plants that live in the water? There are four categories of aquatic plants, or plants that live in the water. The four categories are submerged, floating, emergent and shoreline. While shoreline plants live in the zone between land and water, submerged plants live entirely under the water. Plants that grow in water without soil are referred to as floating. Floating plants usually have roots that float along with the plant, and emergent plants root in the soil under the water and grow most of their leaves and stems above the water.

All types of water plants are essential to aquatic systems because they add oxygen to the water, recycle nutrients, feed fish and other invertebrates and prevent erosion by holding the soil in place with their roots. There are many species of illegal and invasive aquatic plants in the United States, so if you are planting a water garden, choose varieties carefully and seek out aquatic plants that are native to your area.

Submerged plants grow completely underwater, and are also referred to as oxygenating plants. Submerged plants are rooted in the soil at the bottom of the water, and their leaves and stems also grow underwater.

Examples of underwater plants include coontail (​Ceratophyllum demersum​), gray fanwort (​Cabomba caroliniana​), little floating heart (​Nymphoides cordata​), eelgrass (​Vallisneria americana​) and underwater banana plant (​Nymphoides aquatica​).

Some species of pondweed and bladderwort are also examples of submerged plants. Invasive aquatic plants such as water chestnuts (​Trapa natans​) should be removed from lakes and rivers to allow other water plants to thrive.

Some floating water plants are rooted in the soil at the bottom of the water, with leaves that float on the surface of the water. Other floating water plants are not rooted in the soil at all; both their leaves and roots float.

Many of the most well-known aquatic plants are floating water plants. Some examples of floating water plants are Asian lotus (​Nelumbo nucifera​), American lotus (​Nelumbo lutea​), and both tropical and hardy water lilies (​Nymphaea spp​.).

Emergent plants root in the soil under the water, with the larger parts of the plant growing above the water. Many rushes and cattails belong to this group. This type of water plant often grows along the edges of water bodies, where the water is shallow.

A few examples of emergent water plants are the following species: club rush (​Schoenoplectus lacustris​ subsp. ​tabernaemontani​), common arrowhead (​Sagittaria latifolia​), spike rush (​Eliocharis palustris​), hardstem bulrush (​Schoenoplectus acutus​) and common cattail (​Typha latifolia​).

Shoreline plants usually grow in the littoral zone, which is the area of a water body that is closest to shore. Depending on the water level, the roots of plants growing in this zone may be underwater or growing in muddy or mucky soil. Due to their adaptations for living in this area, shoreline plants can survive seasonal flooding.

Shoreline plants are especially important for preventing erosion along the edge of the water. They often provide food and habitat for fish and other animals that live in the water.

Some examples of shoreline plants include blue flag iris (​Iris versicolor​) and many species of mosses. Plants that grow in bogs and wetlands are often the same species as shoreline plants, as the seasonal variation of water provides a similar habitat.

Trees like sycamore (​Platanus occidentalis​), river birch (​Betula nigra​), and many species of willows and mangroves are also commonly found growing along shorelines. Other shoreline species include perennials like swamp milkweed (​Asclepias incarnata​), Joe-Pye weed (​Eupatorium maculatum​) and blue vervain (​Verbena hastata​).