Hymenophyllum tunbrigense, the Tunbridge filmy fern or Tunbridge filmy-fern, is a small, fragile perennial leptosporangiate fern which forms large dense colonies of overlapping leaves from creeping rhizomes. The common name derives from the leaves which are very thin, only a single cell thick, and translucent, giving the appearance of a wet film. The evergreen fronds are bipinnatifid, deeply and irregularly dissected, about 3 to 6 cm long, 2 cm across with dark winged stipes. In contrast to the similar H. wilsonii the fronds are more divided, flattened, appressed to the substrate and tend to have a bluish tint. The fronds are monomorphic and produce sori along the frond segments close to the rachis. Up to 5–10 purse-shaped sori are produced per frond, each covered by two strongly convex, flattened indusial valves. The valve margins are jagged and used to distinguish H. tunbrigense from H. wilsonii, where the edges are entire. In common with all ferns, H. tunbrigense exhibits a gametophyte stage in its life cycle (alternation of generations) and develops a haploid reproductive prothallus as an independent plant. Information about the gametophyte is scarce but it is likely to be inconspicuous with a narrow ribbon-like thallus. The gametophyte may be able to reproduce itself vegetatively by gemmae in the absence of the sporophyte. Gametophytes of the related Killarney fern (Trichomanes speciosum) have been found outside the geographical range of the sporophyte and this may prove to be true of Hymenophyllum tunbrigense.
Tunbridge filmy fern has strong resistance to disease and is generally not susceptible to illnesses. That said, it can be affected by pests and diseases present in its environment. These outbreaks are typically mild. Regarding care, this plant needs moderate maintenance. It should be pruned regularly to preserve a good appearance and encourage healthy growth. Applying fertilizer can also assist in encouraging flowering. Tunbridge filmy fern is appropriate for anyone who has an outdoor area, such as a garden or patio, and does not demand extensive gardening experience. It may need extra attention if cultivated indoors.
How to keep Hymenophyllum Tunbrigense.
Light
Tunbridge filmy fern comes from habitats such as forest understories or rocky areas that provide natural shade. It prefers Full Shade but can tolerate Partial Sun.
Water
The Tunbridge filmy fern, native to moist and shaded environments, thrives in areas with high humidity. It prefers consistent moisture and has moderate drought tolerance. To maintain its health, weekly watering is essential. Additionally, regular misting during its growth cycles enhances its vitality and ornamental appeal, making it an excellent choice for indoor settings.
Temperature
Tunbridge filmy fern can tolerate a wide range of temperatures, but its distribution may still be restricted by particular combinations of moisture and heat. It does best in warm summer conditions with sufficient rainfall or watering. Extended periods of cloudy, rainy weather or prolonged high temperatures can raise the chance of the fern dying. In winter, adequate protection from cold can increase the plant’s survival rate.
Fertilizer
A single spring application of fertilizer is generally enough for Tunbridge filmy fern, though multiple feedings can help it reach maximum growth. Fertilize every month to every month and a half. Feeding improves the leaves' appearance and function, maintaining even color and a healthy texture. It also promotes root development and nutrient uptake, supporting the plant's long-term health.
Pruning
The Tunbridge filmy fern, known for its delicate fronds, requires minimal pruning, which is best done in early to late spring. To promote better airflow and prevent fungal infections, remove any damaged fronds. After pruning, it's important to maintain humidity to minimize stress on the plant. Regular maintenance will promote vigorous growth and ensure the fern's overall health.
Botanical profile.
- Plant Type
- Herb
- Life Cycle
- Perennial
- Genus
- Hymenophyllum
- Family
- Hymenophyllaceae
- Hardiness Zone
- 6-9
- Mature Height
- 2 cm to 5 cm
- Mature Spread
- 3 cm to 10 cm
- Leaf Color
- Dark Green, Forest Green
- Leaf Type
- Semi-evergreen
- Planting Time
- Spring, Summer
- Native Area
- Malawi, Turkey, Honduras, Mexico, Guatemala, Czech Republic, South Africa, Madagascar, Croatia, Gabon, Kenya, Jamaica, Tanzania, Zimbabwe, Colombia, Germany, Italy, Spain, Mozambique, Venezuela, El Salvador, Eswatini, Ireland, United Kingdom, Ecuador, Belgium, Costa Rica, France
Other names.
Reader questions.
What are the sunlight requirements for the Tunbridge filmy fern (Hymenophyllum tunbrigense)?
The Tunbridge filmy fern (Hymenophyllum tunbrigense) thrives in specific sunlight conditions. It requires 'full shade,' which means it should receive less than 3 hours of sunlight daily. Alternatively, it can grow under 'partial sun,' where it would get about 3-6 hours of sunlight. When choosing a spot for your Tunbridge filmy fern, it's crucial to observe the sunlight patterns in your garden throughout the day. Ensure you pick a location that offers an ideal balance of light and shade to make your fern happy, as highlighted by the advice to watch how sunlight gracefully moves through your garden.
