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Wilson's Filmy Fern

Hymenophyllum wilsonii

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Plant Profile

Hymenophyllaceae (Filmy Fern)
Also in this family:
Life Cycle:
Maximum Size:
20 centimetres tall
Cliffs, rocky places, walls, waterside, woodland.
Ferns do not produce flowers.
The spores are in long-stalked pouches near the tips of the leaves. The spores ripen in June and July. The spore pouches are longer stalked than those of Tunbridge Filmy Fern (Hymenophyllum tunbrigense).
A perennial, mat-forming fern. Similar in appearance to Tunbridge Filmy Fern (Hymenophyllum tunbrigense) but with darker green leaves (fronds) which are not flattened and not as forked. The leaf lobes are also longer and unlike Tunbridge Filmy Fern, the veins reach the tips of their leaves.
Wilson's Filmy Fern is not typically known for having a distinct fragrance. Ferns, in general, are not renowned for their aromatic qualities as some other plants might be. The appeal of Wilson's Filmy Fern lies more in its delicate and intricate fronds, creating a visual charm rather than a fragrance experience. If you're seeking plants with fragrant characteristics, ferns may not be the primary choice, as their charm tends to be more visual and less olfactory.
Frequency (UK):
Occasionally seen  

Similar Species

Other Information


Hymenophyllum wilsonii, also known as Wilson's Filmy-fern, is a small and delicate fern species that is native to China and Taiwan. It grows in damp, shady environments, typically in crevices, on damp rocks, and on stream banks.

It is a small and delicate fern, with fronds that reach only a few centimeters in length. The fronds are triangular in shape, with a distinct midrib and fine, threadlike branches that resemble a piece of lace. The leaves are translucent and soft, making them appear "filmy" or "delicate". The sori (clusters of spore-producing structures) are located on the undersides of the fronds, and are protected by reflexed marginal flaps.

Hymenophyllum wilsonii is considered to be an uncommon and endangered species in the wild. It is considered vulnerable, endangered or critically endangered in its native range, due to habitat destruction and degradation, pollution and collection for horticultural use.

It is also a challenging fern to grow in cultivation and is not commonly found in gardens or nurseries. It requires a humid environment, cool temperatures and very moist, humus-rich soil, It also prefers to be grown in shaded or partially shaded locations, but it is not tolerant to frost.

Due to its rarity, collecting it from the wild is prohibited and it is best obtained from reputable nurseries. It should be handled with care to ensure its survival. Conservation efforts have been established to protect remaining wild populations of this species, but it still needs more protection and management to ensure its survival.


Wilson's Filmy Fern, also known as Hymenophyllum wilsonii, is a delicate and beautiful fern species that is native to New Zealand. This plant is known for its filmy, translucent fronds and its preference for damp, shady environments. In this blog post, we will take a closer look at Wilson's Filmy Fern, including its physical characteristics, habitat, and importance in the ecosystem.

Physical Characteristics

Wilson's Filmy Fern is a small fern that typically grows to a height of about 20 centimeters (8 inches). It has delicate fronds that are only one cell thick, giving them a translucent appearance. The fronds are typically about 2-3 centimeters (0.8-1.2 inches) wide and are pinnately divided, meaning that they are divided into small leaflets that are arranged on either side of a central stem. The leaflets are about 1-2 millimeters (0.04-0.08 inches) wide and have a slightly wavy or undulating edge. The fronds are a light green color and have a soft, almost velvety texture.


Wilson's Filmy Fern is found in a variety of damp and shady environments, including forests, gullies, and rocky outcrops. It prefers humid conditions and is often found in areas with a high level of moisture, such as near streams, waterfalls, and other sources of running water. The fern is able to thrive in both sunny and shaded areas, but it tends to grow best in areas with partial shade or dappled sunlight. In its natural habitat, Wilson's Filmy Fern often grows in dense mats or clusters, which can cover large areas of ground.

Importance in the Ecosystem

Wilson's Filmy Fern plays an important role in the ecosystem of New Zealand. As a native species, it is well adapted to the local climate and environment, and it provides a range of benefits to other organisms in the area. For example, the fern provides shelter and habitat for a variety of insects and other small animals, which use the fronds for protection from predators and as a place to rest and feed. In addition, Wilson's Filmy Fern is an important food source for a variety of native birds, including the silvereye, which feeds on the spores produced by the fern.

Conservation Status

Despite its importance in the ecosystem, Wilson's Filmy Fern is considered to be a threatened species in New Zealand. The fern is particularly vulnerable to habitat loss, as many of its preferred environments are being cleared or altered by human activity. In addition, the fern is also threatened by invasive species, such as introduced plants and animals, which can outcompete Wilson's Filmy Fern for resources. To help protect this species, efforts are underway to conserve its habitat and to reduce the impact of invasive species. These efforts include planting native trees and shrubs, controlling invasive species, and creating protected areas where the fern can grow undisturbed.

In conclusion, Wilson's Filmy Fern is a beautiful and important plant species that is native to New Zealand. With its delicate fronds, preference for damp and shady environments, and role in the local ecosystem, this fern is an important part of the natural heritage of the country. While it faces a number of threats, efforts are underway to protect and conserve Wilson's Filmy Fern, ensuring that this unique and valuable plant will continue to thrive in the years to come.

More Information

Wilson's Filmy Fern is not only an important part of the ecosystem in New Zealand, but it is also valued for its ornamental qualities. Its delicate and translucent fronds make it a popular plant for use in terrariums and other indoor displays, as well as for landscaping and garden design.

One interesting feature of Wilson's Filmy Fern is its reproductive strategy. Like other ferns, it reproduces via spores rather than seeds. However, instead of producing spores in clusters or patches on the undersides of its fronds, as many ferns do, Wilson's Filmy Fern produces its spores on tiny, stalked structures called sporangia that are scattered throughout the fronds. The spores are dispersed by the wind and can travel long distances, allowing the fern to spread and colonize new areas.

In addition to its aesthetic and ecological value, Wilson's Filmy Fern is also of cultural significance to the people of New Zealand. In Maori tradition, the fern is known as a koru, which represents new life, growth, and renewal. The koru is a common motif in Maori art and is used in a variety of contexts, from traditional carvings and weaving to modern designs and logos.

One of the unique features of Wilson's Filmy Fern is its ability to adapt to a range of environments. This allows it to survive in a variety of habitats, from moist forest floors to rocky outcrops and crevices. The fern is able to tolerate low light levels and high humidity, and can grow in areas with poor soil quality.

In addition, Wilson's Filmy Fern has a symbiotic relationship with mycorrhizal fungi, which form a mutualistic association with the roots of the fern. The fungi help the fern to absorb nutrients from the soil, while the fern provides the fungi with carbohydrates that it produces through photosynthesis.

Despite its ability to adapt to a range of conditions, Wilson's Filmy Fern is still vulnerable to a number of threats. In addition to habitat loss and invasive species, the fern is also at risk from climate change, which could alter the temperature and rainfall patterns in its native range. In addition, the fern is threatened by over-collection, as it is a popular plant for use in ornamental displays and other commercial applications.

To help protect Wilson's Filmy Fern, it is important to support efforts to conserve its habitat, control invasive species, and reduce the impact of human activities on the natural environment. This includes promoting sustainable land use practices, reducing carbon emissions, and supporting conservation programs that focus on preserving native species and ecosystems. By working together to protect Wilson's Filmy Fern and other important plant species, we can help ensure a healthy and diverse natural world for generations to come.

30 Facts About the Wilson's Filmy Fern

  1. Scientific Name: Wilson's Filmy Fern is scientifically known as Hymenophyllum wilsonii.
  2. Native Habitat: This fern is native to regions with temperate climates, including parts of the United Kingdom.
  3. Location in the UK: Wilson's Filmy Fern can be found in locations such as Eskdale, Cumbria, where it thrives in specific environmental conditions.
  4. Size: The fern typically has small fronds, contributing to an overall delicate appearance.
  5. Filmy Texture: The fronds have a filmy, translucent texture, giving them a unique and delicate quality.
  6. Frond Structure: The fronds are intricately divided, creating a lacy and fine-textured foliage.
  7. Adaptability: Wilson's Filmy Fern is well-adapted to shaded and moist environments, often thriving in the understory of woodlands.
  8. Reproduction: Like many ferns, it reproduces via spores, not seeds, and often forms dense colonies.
  9. Lack of Flowers: Ferns, including Wilson's Filmy Fern, do not produce flowers; instead, they reproduce through spore-bearing structures.
  10. Conservation Status: Depending on local factors and habitat conditions, the conservation status of this fern may vary.
  11. Ecological Role: Ferns play a crucial role in ecosystems by providing habitat for various small organisms and contributing to soil stability.
  12. Ancient Lineage: Ferns are among the oldest plant groups, with a lineage dating back millions of years.
  13. Mossy Environment: Wilson's Filmy Fern might be found in mossy environments, contributing to the overall aesthetic appeal.
  14. Humidity Requirements: Ferns often prefer high humidity levels, contributing to their prevalence in certain forested areas.
  15. Lack of Tracheids: Unlike seed plants, ferns lack tracheids, which are specialized cells for water transport.
  16. Vulnerability to Drying Out: Ferns are vulnerable to drying out and are more commonly found in moist environments.
  17. Habitat Threats: Changes in land use, deforestation, or alterations in water availability can pose threats to fern populations.
  18. Role in Folklore: Ferns, including Wilson's Filmy Fern, have sometimes been featured in folklore and myths.
  19. Medicinal Use: Some ferns have traditional medicinal uses, though Wilson's Filmy Fern is not known for such properties.
  20. Ornamental Use: Due to its delicate appearance, Wilson's Filmy Fern is often cultivated for ornamental purposes in gardens and greenhouses.
  21. Seasonal Changes: The fern's appearance may vary with the seasons, with fronds possibly changing color or texture.
  22. Light Requirements: While often found in shaded areas, ferns may exhibit varying light preferences, including tolerance for low light conditions.
  23. Leaf Venation: The fern's fronds typically exhibit a netted or reticulate venation pattern.
  24. Resilience: Ferns are generally resilient and can recover from damage or disturbance.
  25. Role in Erosion Control: Ferns contribute to soil stability and can be planted for erosion control in certain landscapes.
  26. Hybridization: Some fern species, including Hymenophyllum, may hybridize under certain conditions.
  27. Biodiversity Indicator: Ferns can be indicators of local biodiversity and environmental health.
  28. Role in Carbon Sequestration: Like other plants, ferns contribute to carbon sequestration through photosynthesis.
  29. Fern Allies: While not true ferns, some plants like clubmosses and horsetails are often grouped with ferns as fern allies.
  30. Cultural Significance: Ferns, including Wilson's Filmy Fern, may have cultural significance in certain societies or communities, often symbolizing different attributes.


Distribution Map

Reproduced by kind permission of the BSBI.

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