Davallia epiphylla (Leaf-riding Hare's-foot Fern)
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Davallia epiphylla
Table of Contents
Introduction & Discovery
Davallia epiphylla is one of the most ecologically notable members of the hare's-foot fern family, a diminutive tropical African species that has evolved to grow not only on tree bark and branches like most Davallia but also directly on the living leaves of other plants, a habit known as epiphylly that is rare among ferns and places D. epiphylla in an exclusive ecological guild alongside certain filmy ferns, liverworts, and lichens. The epithet epiphylla, from the Greek epi (upon) and phyllon (leaf), directly references this extraordinary life strategy, in which the fern's fine creeping rhizomes and delicate roots gain purchase on the surface of a large, long-lived rainforest leaf, absorbing moisture and nutrients from rainwater and organic debris that collects on the leaf surface. The strategy requires extraordinary miniaturisation: the rhizome must be thin and lightweight enough not to damage or detach from its leaf substrate, and the fronds must be small and efficient enough to photosynthesize in the deep shade beneath the forest canopy where leaf surfaces accumulate sufficient moisture. The Davalliaceae, a family of about 60 species, is overwhelmingly composed of conventional bark epiphytes, and D. epiphylla's epiphyllous capability is unique or nearly so within the family. Native to the Guineo-Congolian rainforests and East African montane forests, the species inhabits some of the most humid and biodiverse forests on the African continent. In cultivation it is a specialist plant for tropical terrariums and humid greenhouse environments, where its delicate beauty and notable ecology make it a conversation piece of the highest order.
Discovery & Naming
Described from tropical African material with the epithet epiphylla referencing the notable leaf-surface growth habit. The species has been known to pteridologists since colonial-era collections but has remained poorly known in cultivation. The ecology of epiphyllous ferns received renewed scientific attention in the late twentieth century as researchers documented the extraordinary diversity of epiphyll communities in tropical forests.
Native Range & Distribution Map
Distribution map showing the native range of Davallia epiphylla.
Biology & Frond Morphology
Davallia epiphylla belongs to the genus Davallia in the family Davalliaceae, producing evergreen, finely dissected, three times pinnate fronds, 15 to 30 centimetres long, triangular to deltoid in outline. fronds are delicately herbaceous, bright to medium green, with small ultimate segments providing a lacy texture. stipes are slender, 5 to 10 centimetres, straw-coloured, articulate at base. the creeping rhizome is relatively thin (4 to 7 millimetres) compared to some congeners, covered with pale brown to reddish-brown peltate scales. the fine rhizome and small overall plant size are adaptations to the epiphyllous habit, where weight must be minimal to avoid detaching from the leaf substrate. fronds that unfurl from coiled fiddleheads (croziers). Like all ferns, it reproduces via spores borne on the underside of fertile fronds rather than flowers and seeds, and its life cycle alternates between a dominant sporophyte (the visible plant) and a small, short-lived gametophyte stage.
Reproduction & Propagation
Propagation of Davallia epiphylla can be achieved through several methods:
- Spores: Collect ripe spores from the underside of fertile fronds, sow on sterilised peat or peat/perlite mix. Do not cover. Keep humid and in bright indirect light. Prothalli (gametophytes) typically develop in 4–12 weeks, and young sporophytes appear after a further 2–6 months.
- Division: Mature clumps with multiple crowns or creeping rhizomes can be divided in spring as new fronds emerge.
- Rhizome cuttings / offsets: Epiphytic genera (Davallia, Polypodium, Phlebodium) can be propagated from 5–10 cm rhizome segments with at least one frond and visible roots.
Cultivation & Substrate
Successful cultivation of Davallia epiphylla depends on matching three conditions to its natural habitat: consistent moisture without waterlogging, a humus-rich yet well-drained substrate, and the correct light level for its frond type — whether dappled woodland shade, bright filtered light, or, for a handful of rock ferns, direct sun.
Substrate: Minimal: thin layer of sphagnum on cork bark or tree fern slab. Or mounted directly on bark with no substrate. In terrariums, attach to hardscape with fine fishing line and allow to naturalise. Slightly acidic, pH 5.5 to 6.5. Excellent. The epiphytic and epiphyllous habit requires free air circulation around roots. No standing water. Very low. Monthly highly diluted fertiliser only. The species is adapted to extremely nutrient-poor epiphytic conditions. Minimal. Thin sphagnum layer at most. The species obtains nutrients from atmospheric deposition and throughfall.
Water: Rainwater or soft tap
Light: Moderate indirect light to shade. The tropical forest canopy and epiphyllous habitat provide low to moderate diffuse light. In cultivation, avoid direct sunlight. Provide 5,000 to 10,000 lux. The species thrives in the dimmest conditions acceptable for Davallia cultivation.
Humidity: 50-80%
Common Mistakes to Avoid
Attempting to grow in open air. The species requires enclosed humid conditions. Insufficient humidity is the most common cause of failure. Growing too bright; the species prefers shade. Using conventional potting mixes that are too heavy and moisture-retentive for the fine epiphytic root system.
Seasonal Considerations
Minimal seasonal variation in the equatorial habitat. In cultivation, maintain consistent conditions year-round. Reduce feeding slightly in winter if growth slows under reduced light. Never allow temperature to drop below 18 degrees Celsius or humidity below 70 percent.
Diseases & Pests
Common issues affecting Davallia epiphylla in cultivation:
- Root/rhizome rot: Caused by waterlogged substrate, compacted soil, or overwatering in cool weather. Ensure the growing medium is well-aerated and never let pots sit in standing water for prolonged periods.
- Fungal leaf spot & Botrytis: Brown or grey blotches appear in stagnant, overly humid conditions. Improve air circulation, remove affected fronds, and avoid wetting foliage late in the day.
- Scale insects & mealybugs: The most common fern pests, hiding on stipes and frond undersides. Wipe off with a cotton swab dipped in diluted isopropyl alcohol, or treat with horticultural soap. Many chemical pesticides scorch fern fronds — always test on one frond first.
- Spider mites: Fine webbing and stippled fronds, common in dry indoor air. Raise humidity and rinse fronds regularly with tepid water.
- Frond browning (tip burn): Caused by dry air, direct hot sun, fluoridated or chlorinated tap water (especially in Nephrolepis, Calathea-loving filmy ferns), or soluble-salt build-up from fertiliser. Flush the pot with rainwater and reduce feeding.
Indoor Growing & Terrariums
Davallia epiphylla can be grown indoors as a houseplant or terrarium subject when its humidity and light requirements are met.
Indoor Setup
- Light: Bright indirect light — an east- or north-facing window, or 30–60 cm under an LED grow light (10–12 hours/day). Most ferns scorch in direct midday sun.
- Humidity: 50–80%. Group plants, stand pots on a pebble-and-water tray, or run a humidifier; misting alone rarely raises ambient humidity enough.
- Temperature: 16–24°C (60–75°F) for most indoor species; avoid cold drafts and hot radiators.
- Substrate: Peat-free potting mix with added perlite and orchid bark for drainage; epiphytic genera (Platycerium, Davallia) grow best mounted on bark or in a bark-heavy orchid mix.
- Water: Keep consistently moist but never waterlogged. Let the top 1–2 cm of substrate dry slightly between waterings in winter.
- Air circulation: A gentle fan discourages fungal leaf spot without drying out the fronds.
Landscape & Garden Use
Davallia epiphylla can be used in the garden wherever its hardiness and habitat preferences are matched. Ferns are classic choices for shaded borders, woodland gardens, stumperies, rockeries, stream-side plantings, and ground-cover under trees.
Landscape Tips
- Companions: Hostas, Astilbe, Heuchera, Tiarella, Epimedium, hellebores, snowdrops and other shade-tolerant perennials are classic partners.
- Soil preparation: Incorporate leaf mould or composted bark to improve moisture retention and mimic a forest floor.
- Mulching: A 3–5 cm mulch of chipped bark or leaf litter protects the rhizomes, conserves moisture, and slowly releases nutrients.
- Watering: Establish new plantings with regular deep watering during the first growing season; most hardy ferns need only occasional supplemental irrigation once established.
Conservation & Collector Notes
Not formally assessed by IUCN. The species depends on intact humid tropical rainforest, one of the most threatened habitats in Africa. Deforestation for agriculture, logging, and charcoal production in the Guineo-Congolian forest zone directly reduces available habitat. The epiphyllous habit adds vulnerability, as any reduction in forest humidity below the threshold for epiphyll survival eliminates this component of the species' ecology.
Collector Notes
A specialist's species of great ecological interest. Rare in cultivation outside tropical botanical gardens. Obtaining material may require contacts with tropical African institutions or specialist fern growers. The epiphyllous display potential is unique and scientifically educational. Document any cultivated specimens carefully.
Ethnobotany & Cultural Significance
No documented ethnobotanical uses. The species is too small and inconspicuous to have attracted human attention for practical purposes. The epiphyllous habit was a subject of scientific interest for European pteridologists in the colonial period but has no folk cultural significance.
Frequently Asked Questions
Can I actually grow this fern on the leaves of other plants?
In a terrarium with very high humidity above 85 percent, you can place thin rhizome sections on broad, leathery leaves of plants like Anthurium or philodendron, securing with fine thread. If humidity is sufficient, the rhizome may root onto the leaf surface, replicating the natural epiphyllous habit. This requires patience and consistently high moisture.
Why does this species grow on leaves?
In extremely humid tropical forests, large leaves provide stable, moist platforms that persist for months or years. The fern's thin rhizome and small fronds allow it to survive on the minimal nutrients available from rainwater and organic debris on the leaf surface. This strategy reduces competition for bark space while exploiting an underutilised microhabitat.
Is this the only Davallia that grows on leaves?
Essentially yes. While occasional epiphyllous growth may occur in other small Davallia, D. epiphylla is the only species in which this habit is a regular and documented part of its ecology. Among ferns generally, epiphylly is more common in filmy ferns and Grammitidaceae.
Can I grow this without a terrarium?
Not successfully in most climates. The species requires humidity above 75 percent consistently, which is only achievable in enclosed environments or in tropical lowland areas. Even a humidifier is unlikely to maintain adequate conditions in an open room.
How small is this species?
Quite small. Individual fronds are typically 15 to 25 centimetres long with very fine segments, and the rhizome is only 4 to 7 millimetres thick. A mature colony covering a 20-centimetre piece of bark would be considered a well-developed specimen in cultivation.
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Quick Reference Summary: Davallia epiphylla
Golden Rule: Match moisture, light and humidity to each fern’s natural habitat — woodland ferns need shade and humus, rock ferns need drainage, filmy ferns need constant humidity.
Davallia epiphylla is a diminutive tropical African hare's-foot fern notable for its epiphyllous habit, growing not only on tree bark but also on the living leaves of other rainforest plants. With its thin creeping rhizome and delicately dissected fronds, it represents the extreme miniaturisation end of the Davalliaceae spectrum. Native to the humid Guineo-Congolian rainforests and East African montane forests, it requires consistent tropical warmth above 18 degrees Celsius and humidity above 75 percent, making it suitable only for enclosed terrarium or greenhouse culture in temperate climates. A specialist's species of great ecological fascination, it offers the unique opportunity to replicate the rare epiphyllous fern community in a controlled setting.