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Floating Sweet-grass

Glyceria fluitans

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Plant Profile

Flowering Months:
Poaceae (Grass)
Also in this family:
Alpine Catstail, Alpine Foxtail, Alpine Meadow-grass, Annual Beard-grass, Annual Meadow-grass, Arrow Bamboo, Barren Brome Grass, Bearded Couch Grass, Bearded Fescue, Bermuda Grass, Black Bent, Black Grass, Blue Fescue, Blue Moor-grass, Bog Hair-grass, Borrer's Saltmarsh Grass, Bread Wheat, Bristle Bent, Brown Bent, Brown Sedge, Bulbous Foxtail, Bulbous Meadow-grass, California Brome Grass, Canary Grass, Carnation Sedge, Cocksfoot, Cockspur, Common Bent, Common Cord-grass, Common Millet, Common Reed, Common Saltmarsh Grass, Compact Brome Grass, Corn, Couch Grass, Creeping Bent, Creeping Soft-grass, Crested Dog's-tail, Crested Hair-grass, Cultivated Oat, Curved Hard Grass, Cut Grass, Dense Silky Bent, Downy Oat-grass, Drooping Brome Grass, Drooping Tor Grass, Dune Fescue, Early Hair-grass, Early Meadow-grass, Early Sand-grass, False Brome Grass, False Oat-grass, Fern Grass, Fine-leaved Sheep's Fescue, Flattened Meadow-grass, Foxtail Barley, French Oat, Giant Fescue, Glaucous Meadow-grass, Great Brome Grass, Greater Quaking Grass, Grey Hair-grass, Hairy Brome Grass, Hairy Finger-grass, Hard Fescue, Hard Grass, Harestail Grass, Heath Grass, Holy Grass, Hybrid Marram Grass, Italian Rye Grass, Knotroot Bristlegrass, Lesser Hairy Brome Grass, Lesser Quaking Grass, Loose Silky Bent, Lyme Grass, Marram Grass, Marsh Foxtail, Mat Grass, Mat-grass Fescue, Meadow Barley, Meadow Fescue, Meadow Foxtail, Meadow Oat-grass, Mountain Melick, Narrow-leaved Meadow-grass, Narrow-leaved Small-reed, Neglected Couch Grass, Nit Grass, Orange Foxtail, Pampas Grass, Perennial Rye Grass, Plicate Sweet-grass, Purple Moor-grass, Purple Small-reed, Purple-stem Catstail, Quaking Grass, Ratstail Fescue, Red Fescue, Reed Canary Grass, Reed Sweet-grass, Reflexed Saltmarsh Grass, Rescue Grass, Rough Meadow-grass, Rush-leaved Fescue, Sand Catstail, Sand Couch Grass, Scandinavian Small-reed, Scottish Small-reed, Sea Barley, Sea Couch Grass, Sea Fern Grass, Sheep's Fescue, Silver Hair-grass, Six-rowed Barley, Slender Brome Grass, Small Cord-grass, Small Sweet-grass, Smaller Catstail, Smooth Brome Grass, Smooth Cord-grass, Smooth Finger-grass, Smooth Meadow-grass, Soft Brome Grass, Somerset Hair-grass, Sorghum, Spreading Meadow-grass, Squirreltail Fescue, Stiff Brome Grass, Stiff Saltmarsh Grass, Sweet Vernal Grass, Tall Fescue, Timothy Grass, Tor Grass, Tufted Hair-grass, Two-rowed Barley, Upright Brome Grass, Velvet Bent, Viviparous Fescue, Wall Barley, Wavy Hair-grass, Wavy Meadow-grass, Whorl Grass, Wild Oat, Wood Barley, Wood Fescue, Wood Meadow-grass, Wood Melick, Wood Millet, Yellow Oat-grass, Yorkshire Fog
Life Cycle:
Maximum Size:
180 centimetres tall
Ditches, floodplains, marshes, meadows, ponds, riversides, swamps, water, waterside, wetland.

Green, no petals
The flowers are nodding. Clusters of elongated spikelets. Pointed lemmas. Wind pollinated.
Minute seeds.
The stiff-looking green leaves are frequently seen floating in water. Leaf blades have a long, sharply pointed ligule. Perennial.
Other Names:
Float Grass, Floating Manna Grass, Flote Grass, Manna Croup, Manna Grass, Poland Manna, Sweet Grass, Water Manna Grass.
Frequency (UK):

Similar Species

Other Information


Glyceria fluitans, commonly known as floating sweetgrass, is a species of grass in the Poaceae family. It is native to North America, Europe, and Asia and typically grows in wetland habitats such as marshes, swamps, and wet meadows. The plant has long, narrow leaves that float on the water's surface and small, inconspicuous flowers. It is commonly used as a food source for waterfowl and other wetland animals. It is also used in landscaping and restoration projects to provide cover and habitat for wildlife.


Floating Sweet-grass, also known as Glyceria fluitans, is a perennial grass that is native to North America, Europe, and Asia. It is a semi-aquatic plant that typically grows in shallow water or along the banks of streams, ponds, and lakes.

Physical Description

Floating Sweet-grass is a tall, slender plant that can grow up to 6 feet in height. It has long, thin leaves that are typically 10-20 cm in length and 5-15 mm wide. The leaves are flat and have a distinct midrib that runs down the center. The plant also produces long, slender flower spikes that can grow up to 20 cm in length.

Habitat and Distribution

Floating Sweet-grass is found in a wide range of wetland habitats, including marshes, swamps, and bogs. It is also commonly found in slow-moving streams, ponds, and lakes. The plant is distributed throughout North America, Europe, and Asia, and is considered invasive in some areas.

Ecological Importance

Floating Sweet-grass is an important plant in wetland ecosystems. It provides food and habitat for a variety of aquatic and semi-aquatic animals, including insects, fish, and waterfowl. The plant also helps to stabilize stream banks and reduce erosion, and can improve water quality by absorbing excess nutrients and pollutants.

Cultural Significance

Floating Sweet-grass has cultural significance for many Indigenous communities throughout North America. It is used in traditional ceremonies and is considered a sacred plant. The plant is also used for medicinal purposes, and is believed to have a variety of healing properties.

Conservation Status

Floating Sweet-grass is not considered a threatened or endangered species. However, like many wetland plants, it is vulnerable to habitat loss and degradation due to human activities such as development, agriculture, and pollution.

Invasive Potential

While Floating Sweet-grass is native to many parts of the world, it has become invasive in some areas where it has been introduced. The plant can form dense mats that crowd out native vegetation and alter aquatic ecosystems. As a result, it is important to carefully manage the spread of this plant and prevent it from becoming a problem in new areas.

Floating Sweet-grass is an important plant in wetland ecosystems, providing food and habitat for a variety of animals and helping to improve water quality. The plant also has cultural significance for many Indigenous communities and is used for medicinal purposes. While it is not considered a threatened species, it is important to manage the spread of this plant and prevent it from becoming invasive in new areas.

Uses and Benefits

In addition to its cultural significance, Floating Sweet-grass also has a number of practical uses. The plant is commonly used in landscaping and erosion control, and is often planted along the banks of streams and ponds. It is also used as a natural filter for wastewater treatment, as it is capable of absorbing excess nutrients and pollutants from the water.

As a food source, the young shoots and leaves of Floating Sweet-grass can be harvested and eaten raw or cooked. The plant has a sweet, nutty flavor and is rich in nutrients such as vitamin C and potassium.

Challenges and Management

While Floating Sweet-grass is an important plant in wetland ecosystems, it can become invasive in certain areas where it has been introduced. This can lead to a number of ecological challenges, including the displacement of native plant species and changes to water flow and quality.

To manage the spread of Floating Sweet-grass, it is important to prevent the plant from being introduced to new areas and to monitor its growth in existing populations. This can be achieved through a combination of physical removal, herbicide application, and other management strategies.

In areas where Floating Sweet-grass is not considered invasive, the plant can be a valuable addition to wetland restoration projects and other efforts to promote healthy ecosystems.

Floating Sweet-grass is a valuable plant that plays an important role in wetland ecosystems. From its cultural significance to its practical uses, this plant has a wide range of benefits and applications. As we work to protect and restore wetlands around the world, it is important to consider the role that Floating Sweet-grass and other native plant species play in maintaining the health and vitality of these important ecosystems.

Propagation and Cultivation

Floating Sweet-grass is a relatively easy plant to propagate and grow, making it a popular choice for wetland restoration and landscaping projects. The plant can be grown from seed or vegetatively, and is typically planted in the spring or fall when water temperatures are optimal for growth.

To propagate Floating Sweet-grass from seed, the seeds should be collected in the fall and stored in a cool, dry place until they are ready to be planted in the spring. Before planting, the seeds should be stratified to improve germination rates.

To propagate the plant vegetatively, sections of the rhizomes can be cut and replanted in new areas. This can be a more efficient way to establish new populations of the plant, as it allows for faster growth and spread.

When cultivating Floating Sweet-grass, it is important to ensure that the plants have access to adequate water and nutrients. The plant prefers full sun to partial shade and can tolerate a wide range of soil conditions. However, the plant is best suited to wet or moist soils and is not well adapted to dry conditions.


Floating Sweet-grass is a valuable plant that provides a range of ecological, cultural, and practical benefits. From its use in wetland restoration to its role in traditional ceremonies, this plant is an important part of many different landscapes and ecosystems. As we work to protect and restore wetlands around the world, it is important to consider the role that Floating Sweet-grass and other native plant species can play in maintaining the health and vitality of these important ecosystems.