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Word of the Week: Hydrophyte

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Welcome to Word of the Week! This week we want to teach you a word related to plants and water. The term for this Friday is hydrophyte! Stay tuned for a new word each Wednesday to amp up your nature vocabulary!

What Does Hydrophyte Mean?

Hydrophyte [HAHY-druh-fahyt] (noun): A plant that is adapted to living either in waterlogged soil or partly or wholly submerged in water.

What are Hydrophyte Plants? 

Hydrophytes are also known as aquatic plants or aquatic macrophytes. To survive hydrophytes need to be either completely submerged in the water or in some cases need to float on the surface of the water. These plants can be categorized into four main types.

Floating Plants

Floating plants are exactly what the name says, they are plants that float on the water. They are an important part of keeping a pond healthy because they help cover the surface of the water, providing shade for the water below. This shade stops the water from overheating, protecting aquatic organisms and it helps inhibit algae since algae thrive in direct sunlight.

Deep Water Plants

Deep water plants are those plants that you will find deep in the water. They will typically grow on the surface of the water making them look like a floating plant that is anchored to the ground.

Marginal Plants

These hydrophytes are plants that are within the pond inside a planting pot. These will be placed deep enough into the water so that only a couple of inches of the water covers the pot of the plant and the rest of the plant will be out in the air. Marginal plants offer a great natural filtration. If you have a makeshift pond at home we recommend building a shallow shelf to help make sure the plants stay partly in the water.

Oxygenating Plants

Finally, we have oxygenating plants. Oxygenating plants will grow on your pond and will create oxygen that will go into the water. While they do this, they also clean the water by feeding on any organic material that is decaying like leaves or fish waste. When you have a high level of oxygen in your water it can help keep algae growth under control. Furthermore, if you want your fish to survive there needs to be a certain level of oxygen in the water.

Though these plants have many similarities to plants that live on the surface, they also have many unique qualities that make them stand out

First is their water retention ability. Most plants to help them survive will absorb and retain water during the water cycle. However, since these hydrophytes are submerged in the water they don’t need to engage in the process of retaining water.

To help these plants stay floating on water, most of them will have flat leaves to facilitate floating on the water’s surface. An example is the water lily that will have up to 12 inches in leaf diameter.

Because hydrophytes are supported by water rather than roots and stem structures, these plants will have small feathery roots. These roots will help them take in oxygen from the water and, because they are in the water all the time they don’t need long thick roots.

Usually found on floating plants, these hydrophytes will have air sacs to assist with flotation. It’s important to know that some aquatic plants will float slightly submerged in the water, while others will float on top of the surface.

Common Hydrophytes That Can be Found Throughout High Park

In High Park we have many hydrophytes that can be found throughout many of our wetland environments. They may be emergent, submergent, or floating along the shallow edges of ponds and lakes. They provide cover for fish, and habitat for aquatic invertebrates and other wildlife.


The sweet flag is a grass-like low maintenance plant. It grows in moist soil or in several inches of standing water. Sweet flags will spread out slowly over time through rhizomes (stems that grow underground) and will form a dense ground cover but they are not invasive. Though these plants are commonly a green glass colour they can also come in different shades. Some varieties will have a gold strip on one side and a green strip one another

Broad-leaved Cattail

The broad-leaved cattail, also known as Typha latifolia, is found as a native plant species in North America, South America, Eurasia, and Africa. These plants can be found in a variety of different climates such as tropical, subtropical, dry continental, and more. Traditionally this plant has been a part of Indigenous cultures as a source of food and medicine. The rhizomes of these plants are edible after cooking and the skin has been removed.

Common Arrowhead

Also known as the broadleaf arrowhead, this is a perennial aquatic plant. Its name comes from its distinctive arrowhead-shaped leaves. Another common name for this plant is duck potato, in reference to the large starchy golf ball-sized tubers that you will find at the end of these plant rhizomes.

The common arrowhead will bloom in mid to late summer with white three petal flowers usually growing in whorls of three. Like the broad-leaved cattail, the tubers of these plants are edible. The best time to collect them is in the fall or early spring.

Blue-Flag Iris

Finally, we have the beautiful blue-flag iris. The blue-flag iris are low maintenance plants that will flourish in wet areas around woods and meadows, plus along the shorelines of rivers, lakes and ponds. These blue and white flowers will attract many pollinators such as hummingbirds, bumblebees, butterflies, moths and other insects. It can also act as a shelter to animals that live along the shoreline.

On your next visit to High Park’s Grenadier Pond or other wetland environments, take a moment to notice all of the amazing hydrophytes around you! You never know, maybe these plants will inspire you to build your own makeshift pond at home!