Hydrophytes: Indoor and Outdoor Water Garden Plants
What Are Hydrophytes?
Hydrophytes (Greek: hýdōr (water) + Greek phuton (plant)) are water-dependent plants found in aquatic or wet regions of the world. Hydrophytes grow around water bodies, and they can either be found floating, partially, or fully submerged in water.
The nutrients required by hydrophytes are provided within the water. They are common plants found in waterlogged areas. They are also a predominant feature of indoor and outdoor water gardens and ponds.
Water Adaptions of Hydrophytes
Hydrophytes are different from xerophytes, which are terrestrial plants adapted and suited for dry and arid environments. In fact, they are considered opposites. Hydrophytes have different water adaptations that enable them to survive aquatic environments.
They are sometimes completely submerged in water, floating on the top surface, or sometimes crawling at the bottom. These adaptations may differ based on the plant’s level of water dependency, but they all share some important common water adaptation features.
- Flat Leaves: Flat leaves are common in most floating hydrophytes, and they serve as floating portions of the plant. Several hydrophytes also have air sacks that help the plant float. These flat leaves are usually larger in floating hydrophytes compared to the submerged hydrophyte plant leaves, which are thin and long.
- Small Roots: The roots are usually submerged in water. Therefore, there is less need for a strong root and stem structure for support. They have small feathery roots designed to take in oxygen from the water.
- Stems: Stems usually vary in length and size. Submerged hydrophytes have long and thin stems, and floating hydrophytes have thick and short stems that allow them to float.
- Water Retention: Hydrophytes are aquatic plants. Therefore, the leaves, stems, and root structures are less designed for water retention compared to other non-aquatic plants. Stomata are not present in some hydrophytes, and xylem are usually poorly developed because water absorption takes place in most parts of the plant.
Common Types of Hydrophytes
There are many types of hydrophytic or aquatic plants. Some can be seen floating in ponds, while others are submerged and can be seen at the bottom of the pond or in fish tanks. Others are less fancied hydrophytic plants, such as algae, found in virtually all wet aquatic regions. There are, however, some common hydrophytic plants found in indoor and outdoor aquatic gardens.
Lotus
The lotus (Nelumbo nucifera) is a popular water garden plant. Common types include the white and pink lotus flower. The symbolic meaning of the lotus flower includes beauty, royalty, grace, fertility, wealth, and knowledge. In pop culture, it is associated with the order of the white lotus.
Water Poppies
The water poppy (Hydrocleys nymphoides) are tiny, bright yellow flowers found in ponds. In addition to their beautiful scenic yellow view, they also provide shade for fish with their long stems.
Marsh Marigold
Marsh Marigold (Caltha palustris) is a bright yellow perennial plant that signifies the start of spring. The buttercup-like yellow flowers are usually seen around water ponds at the beginning of spring—a welcome view in any water garden.
Pygmy Water Lily
Pygmy water lily (Nymphaea tetragona) is a herbaceous perennial hydrophyte and the smallest water lily in the world. Their small size and bright-colored flowers make them ideal for small aquatic gardens and good for beginners or enthusiasts that are planning to grow an aquatic garden.
Water Caltrops
Water Caltrops are any species classified to belong to one of the three genera: Trapa natans, Trapa bicornis, and Trapa rossica. They are popularly known for producing different types of nuts, which include the trapa nuts, water chestnuts, buffalo nuts, and bat nuts. Most water caltrops do not produce attractive flowers, but the plant remains an attractive water garden hydrophyte, as well as a valuable food source from the produced nuts.
Water Hyacinth
Water Hyacinth (Eichhornia crassipes) is an aquatic plant that belongs to the pickerelweed family. Considered a nuisance weed in many regions, its high growth rates and invasive potential are capable of overwhelming a water body and are thus difficult to control in large water bodies. They are, however, easily controlled in a small outdoor garden or fish pond and have beautiful purple flowers that add to the aesthetic view of the garden.
Salvinia
Salvinia (Salvinia molesta) is another hydrophyte considered an invasive weed that grows rapidly and can cover large water bodies in a short period of time. In a small backyard water garden, however, these plants can be controlled, and their fern-like appearance mixed with other hydrophytes can add a beautiful aesthetic view of the garden.
Typha
Typha is a group of herbaceous perennial plants characterized by long, grass-like leaves. They usually have a long, cylindrical brown fruit that resembles a sausage on a stick. These hydrophytes are commonly known as club rushes, cattails, reedmaces, and bulrushes. They are common in marshes but can also be found in backyard ponds, and they are sometimes kept as water garden plants. If left uncontrolled, their invasive nature can turn them into weeds.
Vallisneria
Vallisneria is a group of freshwater aquatic plants commonly known as eelgrass. They belong to the group of hydrophytes that are fully submerged in water. They are popular indoor water gardens, aquariums, and fish tank plants. They are easy to manage, easily grow, and resemble the vegetation found at the bottom of the sea or ocean.
Ceratophyllum
Ceratophyllum comprises several species of aquatic hydrophytes that are mostly found in freshwater habitats and regions. They are commonly known as hornworts or coontails. They also belong to a group of hydrophytes that can survive fully submerged in water, even though other species are known to float on the surface. Their popularity can be found in aquariums, fish tanks, and indoor water gardens.
Algae
Algae are perhaps the least favorite hydrophyte. They can develop quickly in any water-rich environment. Algae are capable of floating on the top surface of the pond, appearing in the form of a blanket covering the bottom surface of the pond and even on rock surfaces surrounding the pond. If left unchecked, they are capable of overwhelming the entire pond, depriving other plants of their nutrients and oxygen, killing many water lifeforms, and thereby causing a horrible smell around the pond.
Still, algae play an important ecological role in aquatic environments and will likely appear uninvited in any indoor or outdoor water garden.
Should You Grow Your Own Hydrophyte Garden?
Hydrophytes are not the easiest plants to keep in the absence of a constant supply of water. However, they are easier to manage if the water is readily available. They can be easily transferred from outdoors to indoors, and compared to other plants, they are less dependent on soil structure and composition, meaning they can be kept anywhere.
A simple aquatic garden can be started in a small pond of water with a handful of hydrophytes. The rocks around the pond can be occupied by their xerophytic counterparts to create a better aesthetic view.
© 2020 AL