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Lesser Marshwort

Apium inundatum

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:
Apiaceae (Carrot)
Life Cycle:
Maximum Size:
50 centimetres tall
Ditches, marshes, ponds, sand dunes, seaside, water, waterside.

White, 5 petals
Minute white flowers which appear above the water in small, tight but few-flowered clusters (umbels). Flowers have no lower bracts.
The fruit is a well-ridged, elliptic to oval capsule, up to 3mm in length.
A perennial sprawling or creeping plant with submerged, thread-like leaves divided into segments (2-pinnate) and upper leaves with narrow leaflets (1-pinnate). The upper leaves have broader segments than the lower leaves. The stems are often floating or lying along the ground.
Other Names:
Lesser Water Parsnip, Marshwort, Water Celery.
Frequency (UK):
Occasionally seen  

Similar Species

Other Information


Apium inundatum, also known as water celery, is a perennial herbaceous plant that is native to wetlands and shallow water of Europe and North America. It typically grows to heights of up to 50 cm. The plant has green, glossy leaves that resemble celery leaves and small, white or yellow flowers that bloom in summer. This plant is often used as an ornamental plant in water gardens, and also has medicinal properties. It's root can be used to make a tea that is used to relieve sore throat and cough. However, it's considered as a invasive species in some parts of the world and can outcompete native species for resources.


Lesser Marshwort, also known as Apium inundatum, is a flowering plant that belongs to the Apiaceae family. This plant is native to Europe, where it can be found growing in marshes, ditches, and wet meadows. Lesser Marshwort is a delicate plant that produces small, white flowers that bloom from June to August.

The plant has a simple stem that can grow up to 50 centimeters in height, and it is characterized by its fern-like leaves that grow in a rosette pattern. The leaves of Lesser Marshwort are finely divided and have a bright green color. The plant also produces umbels of tiny white flowers that have five petals and are arranged in a flat-topped cluster.

Lesser Marshwort is an important plant for wetland habitats, as it provides a valuable source of food and shelter for a variety of animal species. The plant's seeds and leaves are eaten by waterfowl, while the flowers provide nectar for bees and other pollinators. Lesser Marshwort is also an important plant for water filtration, as it can absorb excess nutrients and pollutants from wetland environments.

Despite its ecological importance, Lesser Marshwort is considered a threatened species in many parts of Europe. Habitat destruction, drainage of wetlands, and pollution are the primary threats to this plant's survival. Additionally, climate change is expected to have a significant impact on Lesser Marshwort, as rising temperatures and changes in precipitation patterns may alter its distribution and reproductive success.

Conservation efforts are underway to protect Lesser Marshwort and its habitat. These efforts include habitat restoration, pollution control, and the establishment of protected areas where the plant can thrive. Additionally, raising awareness about the importance of wetlands and the species that inhabit them can help to promote the conservation of Lesser Marshwort and other wetland plants.

Lesser Marshwort is a valuable and important plant for wetland ecosystems. Its delicate flowers and fern-like leaves add to the beauty of these environments, while its ecological role in water filtration and as a food source for wildlife makes it an essential component of wetland habitats. Conservation efforts are necessary to ensure the survival of Lesser Marshwort and to maintain the health and diversity of wetland ecosystems.

Lesser Marshwort is a highly specialized plant that is adapted to grow in wetland environments. Its root system is well-suited for absorbing water and nutrients from the soil, while its leaves have evolved to maximize the plant's ability to photosynthesize in low light conditions. Additionally, the plant's ability to absorb excess nutrients and pollutants from wetland environments makes it a valuable tool for water quality management.

In addition to its ecological importance, Lesser Marshwort has also been used for medicinal purposes. The plant has been traditionally used to treat a variety of ailments, including digestive disorders, headaches, and rheumatism. However, it is important to note that the use of Lesser Marshwort for medicinal purposes should only be done under the guidance of a qualified healthcare professional.

One of the challenges facing the conservation of Lesser Marshwort is the difficulty of cultivating the plant. While it is possible to grow the plant from seed, it can be difficult to establish in a garden setting. Additionally, the plant is highly sensitive to changes in its environment, and may not thrive outside of its native wetland habitats.

Despite these challenges, there is still hope for the conservation of Lesser Marshwort. The establishment of protected areas and habitat restoration projects can help to provide a safe and stable environment for the plant to thrive. Additionally, raising awareness about the importance of wetland ecosystems and the species that inhabit them can help to promote the conservation of Lesser Marshwort and other wetland plants.

In addition to its ecological and medicinal importance, Lesser Marshwort has also been used in traditional cuisine. In some European countries, the plant is used as a flavoring for soups and stews, and its young leaves can be added to salads for a refreshing taste.

However, it is important to note that the consumption of Lesser Marshwort should be done with caution. The plant contains a compound called psoralen, which can cause skin irritation and can make the skin more sensitive to sunlight. Additionally, the plant may accumulate harmful pollutants, such as heavy metals and pesticides, from its environment, which can make it unsafe for consumption.

To ensure the safety of consuming Lesser Marshwort, it is recommended to only consume the plant under the guidance of a qualified expert and to only consume plants that have been grown in clean environments. Additionally, it is important to avoid consuming the plant in large quantities and to properly cook the plant before consumption.

In conclusion, Lesser Marshwort is a versatile plant that has been used for medicinal and culinary purposes. However, caution should be taken when consuming the plant, as it can cause skin irritation and may accumulate harmful pollutants. As with any plant, it is important to only consume Lesser Marshwort under the guidance of a qualified expert and to ensure that the plant has been grown in clean environments.

Distribution Map

Reproduced by kind permission of the BSBI.

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