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Flowering Rush

Butomus umbellatus

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Plant Profile

Flowering Months:
Butomaceae (Flowering-rush)
Life Cycle:
Maximum Size:
150 centimetres tall
Ditches, ponds, swamps, water, waterside, wetland.

Pink, 3 petals
The flowers have 3 rose pink petals and 3 darker pink sepals. They are cup-shaped and about 2cm across. The long-stalked flowers appear in large umbels.
A purple follicle. The seeds ripen in August and September.
An aquatic plant with long, rigid, grass-like leaves. Perennial.
The flowers are fragrant.
Other Names:
Grass Rush, Grassy Rush, Lily Grass, Water Gladiolus.
Frequency (UK):
Occasionally seen  

Other Information


Butomus umbellatus, also known as the flowering rush, is a perennial aquatic plant in the Butomaceae family. It is native to Europe, Asia and North America. The plant has long, narrow leaves and large, pink or white flowers that grow in umbrella-like clusters. It is often found in shallow water or along the edges of ponds and streams. It is considered an invasive species in some parts of North America, where it can outcompete native plant species and disrupt ecosystems. In traditional Chinese medicine, the roots of the plant are used as a diuretic and anti-inflammatory agent.


Flowering Rush, scientifically known as Butomus umbellatus, is a unique aquatic plant species that is native to Europe, Asia, and North Africa. This perennial plant has been introduced to several countries worldwide, including the United States, Canada, and Australia. Although it is often cultivated as an ornamental plant, flowering rush is considered an invasive species in some regions due to its aggressive growth and ability to outcompete native aquatic vegetation.


The flowering rush is a distinctive plant with long, narrow, bright green leaves that grow in a basal rosette. The leaves can reach up to 1.5 meters in length, and they are triangular in cross-section with smooth edges. The flowering rush also produces tall stems that can grow up to 1.2 meters in height. The stems are topped with an umbel of pink to reddish-pink flowers, which bloom in mid-summer.

Habitat and Distribution

The flowering rush is an aquatic plant that grows in freshwater environments such as lakes, ponds, and slow-moving rivers. It prefers shallow water with soft mud or sandy bottoms and can tolerate water depths of up to 2 meters. It is also tolerant of a range of water temperatures and can survive in both still and flowing water.

The plant is native to Europe, Asia, and North Africa, where it grows in wetlands, marshes, and along the banks of slow-moving streams and rivers. It has been introduced to other parts of the world, including North America, where it is considered an invasive species. In the United States, it is most common in the Great Lakes region and the northeastern part of the country.

Ecological Impacts

The flowering rush is considered an invasive species in many parts of the world, including North America, where it can outcompete native aquatic vegetation, reducing biodiversity and altering the ecological balance of aquatic ecosystems. The plant spreads rapidly through vegetative reproduction and by seed, forming dense stands that can be difficult to control.

In addition to its ecological impacts, the flowering rush can also have negative economic and recreational impacts. It can clog waterways, making boating and fishing more difficult, and can reduce the aesthetic value of natural areas.

Management and Control

Due to its invasive nature, management and control of the flowering rush is often necessary in affected areas. Several control methods are available, including physical removal, chemical control, and the use of biological control agents.

Physical removal can be effective for small infestations, but it is labor-intensive and may not be practical for larger areas. Chemical control involves the use of herbicides to kill the plant, but this can have negative impacts on other aquatic organisms and may require a permit in some regions.

Biological control agents, such as the weevil Bagous nodulosus, have been used in some areas to control the flowering rush. These agents feed on the plant and can reduce its growth and reproductive ability.

Ecological Importance

While the flowering rush can be problematic as an invasive species, it also has ecological importance in its native range. The plant provides habitat and food for a variety of aquatic organisms, including insects, fish, and waterfowl. The flowers attract pollinators, such as bees and butterflies, and the seeds provide a food source for water birds.

In addition, the plant can play a role in water quality and nutrient cycling. It can absorb excess nutrients from the water, such as phosphorus and nitrogen, and convert them into plant biomass. This can help to reduce nutrient pollution and improve water quality in affected areas.

Cultural Significance

The flowering rush has been valued for its ornamental qualities for centuries. It has been cultivated in Europe since the 17th century and has been introduced to other regions as an ornamental plant. The plant's tall, striking flowers and long, slender leaves make it a popular addition to water gardens and aquatic landscapes.

In some cultures, the flowering rush also has traditional medicinal uses. The plant has been used to treat a variety of ailments, including skin disorders, menstrual problems, and digestive issues.

Overall, the flowering rush is a unique and interesting aquatic plant that has both positive and negative impacts depending on its context. While it can be a problem as an invasive species, it also has ecological and cultural significance in its native range and as an ornamental plant. Effective management and control methods are necessary to ensure that the plant does not cause harm to native ecosystems while also allowing people to appreciate its beauty and unique qualities.

Reproduction and Growth

The flowering rush reproduces both vegetatively and sexually. It can form dense stands through the production of underground stems called rhizomes, which can sprout new shoots and form new plants. The plant can also produce seeds, which are dispersed by water or animals and can remain viable for several years.

The flowering rush can grow rapidly under favorable conditions, and it is tolerant of a range of environmental factors such as water depth, temperature, and light intensity. It can outcompete native aquatic vegetation and form monocultures, reducing the diversity and abundance of other plant species in affected areas.

Uses and Benefits

While the flowering rush can be problematic as an invasive species, it also has potential uses and benefits. The plant's long, fibrous stems have been used to make paper and textiles in some regions, and the leaves can be used as a natural filter to remove pollutants from water.

In addition, the plant has been studied for its potential as a bioenergy crop. The high biomass production and nutrient uptake of the flowering rush make it a promising candidate for use in bioremediation and biofuel production.

Management and Control

Due to its invasive nature, the flowering rush is considered a noxious weed in many regions and is subject to management and control measures. The best approach for controlling the plant will depend on the size and extent of the infestation, the location, and the resources available.

Manual removal of the plant can be effective for small infestations. This can involve physically digging up the plant and its roots or cutting the plant at its base and removing it from the water. However, manual removal can be time-consuming and labor-intensive, and it may not be practical for large or widespread infestations.

Chemical control methods, such as the use of herbicides, can be effective for larger infestations. However, the use of herbicides can have negative impacts on non-target species and the environment if not used correctly. It is important to follow all regulations and guidelines for the safe and effective use of herbicides.

Prevention is also an important aspect of managing the flowering rush. This can involve taking steps to prevent the introduction and spread of the plant, such as cleaning boats and equipment before moving them between water bodies, and monitoring and reporting any new infestations.

Overall, effective management and control of the flowering rush will require a combination of approaches tailored to the specific situation. It is important to work with local authorities and experts to develop a management plan that takes into account the ecological and cultural context and the potential impacts of control measures.


Flowering Rush filmed at RHS Bridgewater, Lancashire on the 10th September 2022.


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Distribution Map

Reproduced by kind permission of the BSBI.

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