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Marsh Fern

Thelypteris palustris

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Plant Profile

Thelypteridaceae (Marsh Fern)
Also in this family:
Life Cycle:
Maximum Size:
90 centimetres tall
Fens, gardens, marshes, swamps, waterside, wetland, woodland.
Ferns do not possess flowers. Instead they reproduce by means of spores.
The spores ripen during August and September.
The soft, light green leaves (fronds) appear from June to October (deciduous). The stalks are not hairy. Frequently very common in Alder woodland. Perennial.
Other Names:
Blue Marsh Fern, Eastern Marsh Fern, Marsh Shield Fern.
Frequency (UK):

Similar Species

Other Information


Thelypteris palustris, also known as marsh fern, marsh shield fern, or blue marsh fern, is a species of fern that is native to North America. It is a perennial plant that typically grows to be about one to three feet tall. The fronds of T. palustris are deciduous, which means they die back in fall and grow again in spring, and are about 2-3 feet long and 6-12 inches wide. They are divided into many narrow, pointed leaflets, and have a pale blue-green color which gives the plant its common name "blue marsh fern". The fronds are held on dark brown, wiry and erect stipes (stems)

Thelypteris palustris is well adapted to wet and marshy conditions, and it is commonly found in wetland areas, such as marshlands, swamps, and along the edges of ponds and streams. This fern can grow in full sun to heavy shade, but it prefers dappled or filtered sunlight and moist soils with consistent water. It is also tolerant to different pH levels and is considered as a good plant for erosion control.

This fern is a popular ornamental plant, and it can be grown in gardens, along borders, or as a ground cover. It is widely available commercially and considered as an easy plant to grow. It can also be grown indoors, in a terrarium or a well-lit room. Thelypteris palustris is hardy in USDA zones 3-9, and can handle some flooding or standing water. It is a good choice for rain gardens or for low-lying areas of the landscape.


The Marsh Fern, Thelypteris palustris, is a common fern that grows in wetlands, marshes, and swamps across North America. It is also known as the Eastern Marsh Fern, the Meadow Fern, or the Slender Marsh Fern. This fern is easy to identify by its delicate fronds, which are made up of many small, oval-shaped leaflets.

The Marsh Fern is a perennial plant that can grow up to 3 feet tall. It has long, thin fronds that emerge from a central rosette, and each frond can be up to 2 feet long. The leaflets are arranged in a feather-like pattern along the stem, and they are typically a light green color. In the fall, the fern's foliage turns a warm golden color before dying back for the winter.

One of the Marsh Fern's most interesting features is its ability to adapt to wetland environments. It has developed a unique method of reproducing that allows it to survive in areas that are frequently flooded. The fern produces small, spore-filled structures on the undersides of its fronds that are released into the air and carried by the wind to nearby wetland areas. Once they land in a suitable spot, the spores germinate and grow into new ferns.

The Marsh Fern is a valuable part of wetland ecosystems. Its fronds provide cover and nesting habitat for small animals and birds, while its rhizomes help stabilize the soil and prevent erosion. In addition, the fern can absorb excess nutrients from the water, helping to reduce pollution and improve water quality.

For those interested in gardening with native plants, the Marsh Fern is a great choice for a wetland or bog garden. It prefers moist, acidic soil and partial shade, and can be used as a groundcover or planted in groups to create a naturalistic look. It is also deer-resistant, making it a good option for gardens in areas with high deer populations.

The Marsh Fern is a fascinating plant that has adapted to thrive in wetland environments. It is an important part of these ecosystems and provides many benefits to the animals and plants that live there. For gardeners, it is an excellent choice for wetland gardens and can help create a naturalistic look while also providing important ecological benefits.

The Marsh Fern has a long history of use by Native American tribes for both medicinal and culinary purposes. The fern's rhizomes were used to make poultices for treating skin irritations and infections, as well as to alleviate joint pain and inflammation. In addition, the young fronds of the fern were often eaten as a springtime vegetable, either cooked or raw.

While the Marsh Fern is not commonly used in modern herbal medicine, it is still highly valued for its ecological role. The fern is often used in wetland restoration projects to help stabilize soil and prevent erosion, as well as to help filter pollutants from the water. In addition, the fern's ability to grow in wetland environments makes it an important indicator of wetland health.

Despite its many benefits, the Marsh Fern does face some threats in certain areas. Wetland destruction, habitat fragmentation, and invasive species are all major threats to this plant, and its populations have declined in many areas as a result. Efforts are currently underway to protect and restore wetland habitats, which will help to ensure the survival of this important plant species.

One interesting fact about the Marsh Fern is that it is highly adaptable to different environmental conditions. It is able to survive in a variety of wetland habitats, from marshes and swamps to bogs and fens. In addition, the fern is able to tolerate a range of soil types, from sandy to clayey, and is able to grow in both acidic and alkaline soils.

Another interesting feature of the Marsh Fern is its ability to hybridize with other fern species. Hybridization occurs when two different fern species mate and produce offspring with characteristics of both parents. The Marsh Fern has been known to hybridize with several other fern species, including the Cinnamon Fern and the Interrupted Fern.

In addition to its ecological and cultural significance, the Marsh Fern is also a popular ornamental plant. It is often used in landscaping to create a naturalistic look, and its delicate fronds and attractive golden fall foliage make it a beautiful addition to any garden.

Finally, the Marsh Fern has also been the subject of scientific research. It has been studied for its ability to absorb excess nutrients and pollutants from the water, as well as for its potential use in wetland restoration projects. Scientists are also studying the fern's genetics in order to better understand how it has adapted to wetland environments and to develop strategies for conserving and protecting this important species.

In conclusion, the Marsh Fern is a remarkable plant with many interesting features and important ecological and cultural significance. Its adaptability, ability to hybridize, and use in both wetland restoration and ornamental gardening make it a valuable and versatile plant species. As we continue to learn more about the Marsh Fern and its role in wetland ecosystems, we can better appreciate its many benefits and work to protect and conserve this important plant.

Distribution Map

Reproduced by kind permission of the BSBI.

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