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Tunbridge Filmy Fern

Hymenophyllum tunbrigense

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Plant Profile

Hymenophyllaceae (Filmy Fern)
Also in this family:
Life Cycle:
Maximum Size:
10 centimetres tall
Rocky places, waterside, woodland.
The spores ripen in June and July. They live inside stalked pouches near the tips of the leaves.
A perennial, evergreen fern with flattened, dull green leaves (fronds). The fronds are forked several times. The veins do not reach the ends of the fronds. The fronds have a bluish sheen.
Other Names:
Tunbridge Fern, Tunbridge Goldilocks, Tunbridge Wells Filmy Fern.
Frequency (UK):

Similar Species

Other Information


Hymenophyllum tunbrigense, also known as the Tunbridge Filmy-fern, is a small and delicate fern species that is native to the British Isles, Western Europe, and North America. 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 tunbrigense is considered to be a rare and endangered species in the wild. It is considered vulnerable, endangered or critically endangered in the different regions where it is found, due to habitat destruction and degradation, pollution and collection for horticultural use.

It is 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, also 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.


Tunbridge Filmy Fern, scientifically known as Hymenophyllum tunbrigense, is a delicate and beautiful species of fern native to the United Kingdom. It is named after the town of Tunbridge Wells in Kent, where it was first discovered in the 18th century.

Tunbridge Filmy Fern is a small, delicate fern that grows in damp and shady places, often in the crevices of rocks, walls, and tree trunks. It has a slender, wiry stem that is usually less than 10 cm in height, and it produces fronds that are divided into many small, feathery segments. These segments are thin and papery, giving the fern a delicate and airy appearance. The fronds are usually a pale green color, but they can also be tinged with brown or red.

One of the most striking features of Tunbridge Filmy Fern is its reproductive structures, which are borne on separate fronds from the vegetative fronds. The reproductive fronds are much smaller than the vegetative fronds and are covered in tiny, spherical structures called sporangia. These sporangia contain the fern's spores, which are released into the air to propagate the species.

Tunbridge Filmy Fern is a rare species in the United Kingdom, and it is classified as "Vulnerable" on the IUCN Red List of Threatened Species. Its habitat has been threatened by habitat loss and degradation, as well as by the disturbance of rocks and trees that the fern relies on for shelter. In recent years, conservation efforts have been made to protect and restore the fern's habitat, and it is now found in several nature reserves and protected areas.

Tunbridge Filmy Fern has also been of interest to botanists and plant enthusiasts for its delicate and intricate beauty. It is sometimes grown as an ornamental plant in gardens and greenhouses, although it can be challenging to cultivate outside of its native habitat. It requires a moist and humid environment, as well as protection from direct sunlight and wind.

Tunbridge Filmy Fern is a beautiful and delicate species of fern that is native to the United Kingdom. Its unique reproductive structures and delicate fronds make it a fascinating plant to study and admire. However, its rarity and threatened status also make it an important species for conservation and habitat restoration efforts. By protecting and preserving the habitats where Tunbridge Filmy Fern grows, we can ensure that future generations will be able to enjoy this beautiful and unique species of fern.

Tunbridge Filmy Fern belongs to the family Hymenophyllaceae, a family of ferns that are known for their delicate and filmy fronds. The family includes more than 600 species that are found in tropical and temperate regions around the world. The Hymenophyllaceae family is unique among ferns in that their spores are not covered by a protective covering called an indusium, as is the case in most other fern species. Instead, their spores are borne in specialized sporangia that are covered by a thin layer of tissue, giving the ferns their delicate and filmy appearance.

Tunbridge Filmy Fern is a species that is particularly sensitive to changes in its environment, and it is often used as an indicator of habitat quality in ecological studies. The fern is known to be sensitive to changes in temperature, humidity, light, and air pollution, and it can be used to monitor the health of habitats and ecosystems where it is found.

One interesting aspect of Tunbridge Filmy Fern is its historical and cultural significance. The fern was first discovered in the town of Tunbridge Wells in the 18th century, and it quickly became a popular subject of study and fascination among botanists and naturalists of the time. The fern was also incorporated into popular culture, and it became a symbol of the romantic and poetic ideals of the time. The Tunbridge Filmy Fern was often depicted in literature, poetry, and art, and it became a symbol of the beauty and delicacy of nature.

Today, Tunbridge Filmy Fern remains an important species for study and conservation, and it is protected by law in many countries where it is found. Efforts are underway to protect and restore its habitat, and to educate the public about the importance of preserving this unique and delicate species. By protecting Tunbridge Filmy Fern and its habitat, we can ensure that future generations will be able to appreciate and learn from this fascinating and beautiful species of fern.

Tunbridge Filmy Fern is also an important component of many ecosystems where it is found. The fern provides shelter and habitat for a variety of insects and small animals, including snails, slugs, and spiders. The fern's delicate fronds and intricate structure also make it a valuable resource for scientific research, as it can provide insights into the biology and ecology of other fern species.

In addition to its ecological and scientific importance, Tunbridge Filmy Fern also has cultural significance in the communities where it is found. The fern is often celebrated in local festivals and events, and it is featured in the folklore and traditions of many cultures. In some areas, the fern is believed to have medicinal properties and is used in traditional medicine.

Despite its cultural and ecological importance, Tunbridge Filmy Fern remains threatened by habitat loss and degradation. The fern's habitats are often threatened by development, land use change, and pollution, and its populations have declined significantly in recent decades. However, conservation efforts are underway to protect and restore the fern's habitat, and to promote awareness of the importance of preserving this unique and delicate species.

Overall, Tunbridge Filmy Fern is a fascinating and important species that highlights the importance of preserving and protecting biodiversity. Its delicate fronds and unique reproductive structures make it a valuable resource for scientific research, while its ecological and cultural significance make it an important species for conservation and preservation. By working together to protect and preserve this delicate and beautiful species, we can ensure that it continues to inspire and captivate us for generations to come.

Distribution Map

Reproduced by kind permission of the BSBI.

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