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Lesser Pondweed

Potamogeton pusillus

Please keep in mind that it is illegal to uproot a plant without the landowner's consent and care should be taken at all times not to damage wild plants. Wild plants should never be picked for pleasure and some plants are protected by law.
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Plant Profile

Flowering Months:
Potamogetonaceae (Pondweed)
Life Cycle:
Maximum Size:
70 centimetres long
Ditches, gardens, ponds, water.

Green, 4 petals
A small spike of 3 to 6 flowers arranged in whorls.
A small, globular, beaked seed capsule.
Narrow, linear, translucent, mid-green leaves. The leaves are more pointed than those of the similar looking Small Pondweed (Potamogeton berchtoldii).
Other Names:
Least Pondweed, Slender Pondweed, Small Pondweed.
Frequency (UK):
Occasionally seen  

Similar Species

Other Information


Potamogeton pusillus, also known as small pondweed, is a perennial aquatic plant that is native to North America. It is commonly found in freshwater ponds, lakes, rivers, and streams. The leaves are small and typically float on the water's surface, they are lanceolate in shape, with smooth edges. The stems are thin and anchored to the bottom by rhizomes. The flowers are small and inconspicuous, and arranged in spikes at the top of the stem. They typically bloom in late spring to early summer. It is an important food source for waterfowl and aquatic animals, and it also provides cover and habitat for fish and other aquatic organisms. It's considered a good oxygenator for the aquatic ecosystem and it's also used as an ornamental plant in water gardens and ponds.


Lesser Pondweed, scientifically known as Potamogeton pusillus, is a small aquatic plant that belongs to the family Potamogetonaceae. This species is native to Europe, Asia, and North America, and is commonly found in ponds, lakes, and slow-moving streams with calm waters. It is a popular plant among aquatic enthusiasts and has been used in aquariums and ornamental ponds.


Lesser Pondweed is a submerged aquatic plant that typically grows up to 20 cm long. It has slender, light green stems that are cylindrical and unbranched, with small, linear leaves that are arranged in opposite pairs along the stem. The leaves are typically 1-2 cm long and 1-2 mm wide and have a translucent, membranous texture. The plant has small, inconspicuous flowers that are arranged in spike-like clusters at the base of the stem.

Habitat and Distribution

Lesser Pondweed is commonly found in ponds, lakes, and slow-moving streams with calm waters. It prefers shallow, still or slow-moving water bodies with soft or muddy bottoms. This species can tolerate a wide range of water conditions, including low light levels, low oxygen levels, and high levels of dissolved nutrients. It is found in both freshwater and slightly brackish water and can tolerate salinity up to 5 parts per thousand.

Lesser Pondweed is native to Europe, Asia, and North America and has been introduced to other parts of the world, including Australia, New Zealand, and South Africa. In North America, it is found in the northern and eastern parts of the continent, from Alaska to Labrador and south to Texas and Florida.

Ecological Importance

Lesser Pondweed is an important part of the aquatic ecosystem and provides a variety of benefits to both animals and humans. It is a food source for many aquatic animals, including fish, waterfowl, and invertebrates. It also provides habitat and shelter for small aquatic animals, such as insects and snails.

In addition, Lesser Pondweed is an important plant for maintaining water quality. It can absorb excess nutrients, such as nitrogen and phosphorus, from the water, reducing the likelihood of harmful algal blooms. It can also help to stabilize sediment, reducing erosion and improving water clarity.


Lesser Pondweed is a popular plant among aquatic enthusiasts and has been used in aquariums and ornamental ponds. It is a fast-growing plant that can provide oxygen and improve water quality in these settings. It is also an attractive plant with delicate, translucent leaves that can add visual interest to the aquarium or pond.

In addition to its ornamental uses, Lesser Pondweed has also been used in traditional medicine. It has been used to treat a variety of ailments, including digestive disorders, respiratory problems, and skin conditions.

Lesser Pondweed is a small aquatic plant that is native to Europe, Asia, and North America. It is commonly found in ponds, lakes, and slow-moving streams with calm waters and is an important part of the aquatic ecosystem. It provides food and habitat for aquatic animals and can help to improve water quality by absorbing excess nutrients and stabilizing sediment. It is also a popular plant among aquatic enthusiasts and has been used in aquariums and ornamental ponds. With its many benefits, Lesser Pondweed is an important plant for both animals and humans.

More Information

Lesser Pondweed is a versatile plant that has a number of interesting adaptations. For example, its thin, membranous leaves help it to absorb nutrients and sunlight more efficiently, and its ability to grow in a variety of water conditions allows it to thrive in different environments. In addition, the plant can reproduce both sexually and asexually, which allows it to colonize new areas quickly and efficiently.

One of the most interesting aspects of Lesser Pondweed is its use in traditional medicine. The plant has been used for centuries to treat a variety of ailments, particularly those related to the digestive and respiratory systems. It is believed to have anti-inflammatory, antiseptic, and analgesic properties, and has been used to treat conditions such as diarrhea, coughs, and asthma.

In recent years, there has been growing interest in the potential of Lesser Pondweed as a source of bioactive compounds for use in medicine and other applications. Researchers have identified a number of compounds in the plant that have potential therapeutic properties, including anti-inflammatory, antioxidant, and antitumor effects. Some studies have also suggested that Lesser Pondweed extracts may have antimicrobial properties, making them useful in the development of new antibiotics.

Lesser Pondweed is also an important indicator species for water quality monitoring. As it can absorb nutrients from the water, it is often used as a bioindicator of nutrient enrichment and pollution in aquatic environments. The presence of large amounts of Lesser Pondweed can indicate high nutrient levels, which may be harmful to other aquatic organisms.

In addition to its ecological and cultural uses, Lesser Pondweed also has economic importance. It is sometimes harvested for use as a food source for fish and other aquatic animals. In some areas, it is also harvested for use in traditional medicine or as a source of bioactive compounds for the development of new pharmaceuticals.

Despite its many benefits, Lesser Pondweed can also be problematic in some settings. Invasive populations of the plant have been reported in certain areas, where it can outcompete native aquatic plants and disrupt local ecosystems. In addition, excessive growth of Lesser Pondweed can lead to problems such as reduced water flow and oxygen levels, which can have negative effects on aquatic animal populations.

Overall, Lesser Pondweed is a fascinating and important plant with a variety of ecological, cultural, and economic uses. As we continue to learn more about this species, it is likely that we will discover new applications for it in fields such as medicine, agriculture, and environmental conservation. At the same time, it is important to monitor populations of the plant to ensure that it does not become a threat to native aquatic plants and animals.

Distribution Map

Reproduced by kind permission of the BSBI.

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