Introduction & Discovery

Polystichum setiferum is the quintessential cottage garden fern and arguably the most cultivar-rich fern species on the planet. Over 300 named forms were described during the Victorian pteridomania of 1850–1890, when fern-hunting became a national obsession in Britain and collectors paid extravagant sums for crested, plumose and multi-divided sports found in Devon hedgerows and Dorset lane banks. Peter Forskål described the species in 1775 as Polypodium setiferum from Mediterranean material — the epithet means ‘bristle-bearing’, a reference to the fine hair-like tips on each pinnule margin — and Thomas Moore later transferred it to Polystichum, where it sits today within Dryopteridaceae. The species is native across western and southern Europe from Ireland and Norway south through Iberia, the Mediterranean basin and North Africa to the Canary Islands and Azores, with the densest populations in Atlantic climates where mild winters and high rainfall favour its evergreen habit. Fronds are bipinnate, 60–120 cm long, with an arching, soft-textured architecture that gives it a grace no other hardy fern matches. Each pinnule carries a diagnostic basal auricle — a small ‘thumb’ at the acroscopic base — that is the single most reliable field character for separating it from its hard-textured congener P. aculeatum. In the garden, P. setiferum occupies a niche no other fern can fill: dry shade under deciduous trees, where its deep roots reach subsoil moisture and its lime tolerance lets it thrive on chalky soils that would kill most ferns. It is evergreen in mild winters, hardy to −20°C, and requires almost no maintenance beyond an annual mulch of leaf mould. If you could plant only one fern in a temperate garden, this would be the one — and the 300+ cultivars mean you could spend a lifetime collecting without exhausting the variation.

Discovery & Naming

The species was first described by Peter Forskål, the Finnish-Swedish naturalist and student of Linnaeus, who collected material in the eastern Mediterranean and published it in 1775 as Polypodium setiferum in his posthumous Flora Aegyptiaco-Arabica (Forskål had died of plague in Yemen in 1763; his manuscripts were edited and published by Carsten Niebuhr). The epithet setiferum — from Latin seta (bristle) and ferre (to bear) — describes the fine hair-tipped teeth on the pinnule margins. For nearly a century the species was shuffled between genera: it appeared as Aspidium setiferum in Swartz’s Synopsis Filicum (1806), then as Polystichum setiferum when Thomas Moore, the great Victorian pteridologist and curator of the Chelsea Physic Garden, recognised the peltate indusia as the defining character of Polystichum. The combination Polystichum setiferum (Forssk.) T.Moore ex Woyn. was validated by Woynar in 1913. The Victorian pteridomania of 1850–1890 transformed P. setiferum from a common hedgerow plant into the most collected and cultivated fern in Britain. Edward Joseph Lowe, author of Ferns, British and Exotic (1856–1860) and Our Native Ferns (1867–1869), documented hundreds of wild-collected sports and garden variants, illustrating many in detailed chromolithographic plates. Charles Thomas Druery, secretary of the British Pteridological Society and editor of the British Fern Gazette, championed the cultivation and hybridisation of P. setiferum sports from the 1880s through his death in 1917, and coined several cultivar group names still used today. The Stansfield nursery in Southport, Lancashire, was the commercial epicentre: Robert and James Stansfield propagated, named and sold dozens of P. setiferum cultivars from the 1870s onward, and their catalogues remain primary references for cultivar identification. The most celebrated discovery was ‘Plumosum Bevis’, found by a Mr Bevis in a Dorset hedgerow in the 1870s — a plumose form of such exquisite beauty that it has been called the finest cultivar of any hardy fern. Reginald Kaye, nurseryman and author of Hardy Ferns (1968), did more than anyone in the 20th century to rescue and propagate surviving Victorian cultivars. Jimmy Dyce, founder of the Hardy Fern Foundation correspondence in the UK, continued the work into the 1990s. Today Martin Rickard (Fibrex Nurseries) and others maintain National Collections of Polystichum that include some 50–60 surviving Victorian-era cultivars alongside modern selections.

Frond Morphology

Fronds of Polystichum setiferum are bipinnate, lanceolate to broadly lanceolate in outline, 60–120 cm long (occasionally 150 cm in sheltered damp woodland), and 20–35 cm wide at the broadest point, which falls in the lower third of the blade. The overall posture is arching to semi-pendulous, giving mature plants a graceful fountain-like habit quite unlike the stiff upright shuttlecock of Dryopteris filix-mas. The stipe is stout, 15–25 cm long (roughly 15–20% of total frond length), green above and densely clothed below with large ovate-lanceolate scales that are pale brown with a darker central stripe — these scales are larger (8–15 mm) and paler than those of P. aculeatum, and their colour is a useful field character. The rachis is green, slightly flexuous, bearing smaller scales throughout its length. Pinnae number 20–40 pairs, are linear-lanceolate, 8–18 cm long in mid-frond, and set at 60–80° to the rachis. The basal pair of pinnae is slightly shorter and more triangular than those above, never reduced to minute auricles as in some Dryopteris species. Each pinna is divided into 10–20 pairs of pinnules. The pinnules are the species’ signature: each is distinctly stalked (0.5–1.5 mm petiolule), ovate to rhombic, 5–12 mm long, with a strongly developed basal auricle (‘thumb’) on the acroscopic side — this auricle can be as large as 2–3 mm and overlaps the rachilla. The basal acroscopic pinnule of each pinna is conspicuously enlarged, a feature shared with P. aculeatum but more pronounced here. Margins bear fine aristate teeth, each tipped with a translucent bristle (seta) 0.3–0.5 mm long. The texture is soft and pliable — a frond draped over the hand feels like heavy silk, in contrast to P. aculeatum which feels like stiff parchment. Upper surface is dark green, matte to slightly glossy; lower surface paler with scattered small scales along the costae. Venation is pinnate within each pinnule, with forked lateral veins, each vein ending at the margin. The extraordinary variability of frond form is the species’ defining biological feature: the ‘Divisilobum’ group pushes the bipinnate architecture to tripinnate or quadripinnate, with each pinnule further divided into secondary and tertiary pinnulets, producing fronds so finely dissected they resemble green lace. The ‘Plumosum’ group has enlarged, overlapping pinnules that give a plume-like (plumose) effect. The ‘Congestum’ group has pinnae so compressed and overlapping that the frond appears congested and almost three-dimensional. No other fern species on earth displays this range of architectural variation within a single diploid genome.

Native Range & Distribution Map

Distribution map showing the native range of Polystichum setiferum.

Biology & Frond Morphology

The rhizome of Polystichum setiferum is erect and stout, 3–5 cm in diameter, densely clothed in persistent pale brown lanceolate scales 10–15 mm long, and forms a short caudex that lifts the crown 5–15 cm above ground level in mature specimens over 10 years old. Roots are black, wiry and fibrous, penetrating 30–50 cm into mineral subsoil — considerably deeper than most woodland ferns, which explains the species’ exceptional drought tolerance once established. Fronds are bipinnate with a broadly lanceolate to ovate-lanceolate outline, 60–120 cm long and 20–35 cm wide, arching gracefully from the crown to create a vase-shaped rosette of 10–20 fronds at maturity. The stipe is short (10–20% of total frond length), stout, densely covered at the base with large ovate pointed pale brown scales that become sparser toward the rachis. Each frond carries 20–40 pairs of pinnae; each pinna is further divided into 10–20 pairs of pinnules. The pinnules are the diagnostic feature: each is distinctly stalked (petiolulate), with a pronounced basal auricle (‘thumb’) on the acroscopic side — this stalked, thumbed pinnule is the key character separating P. setiferum from P. aculeatum, where pinnules are sessile and decurrent. The pinnule margin bears fine bristle-like teeth (setae), each tipped with a hair point — hence setiferum, ‘bristle-bearing’. The texture is soft compared to other Polystichum species, lacking the rigid glossy surface of P. aculeatum. Sori are circular, 1.0–1.5 mm diameter, borne in two rows flanking the pinnule midvein, and covered by a peltate (umbrella-shaped, centrally attached) indusium — a diagnostic distinction from the reniform (kidney-shaped) indusia of Dryopteris. Spores are bilateral, dark brown, 28–35 μm. The chromosome count is 2n = 82 (base number x = 41), making it a straightforward diploid within a genus rife with polyploids and hybrids. The morphological variability of this species is extraordinary and unmatched in ferns: normal bipinnate forms grade through crested (frond tip branched), plumose (pinnules enlarged, overlapping, feathery), congested (pinnae compressed, overlapping), to quadripinnate forms in the ‘Divisilobum’ group where each pinnule is further divided twice more, producing fronds of notable lace-like complexity. Some cultivars produce bulbils (vegetative plantlets) along the rachis and even on the stipe — a viviparous habit unusual among ferns and valuable for propagation of cultivars that do not come true from spores.

Spore Dispersal

Sori are circular, 1.0–1.5 mm in diameter, borne in two distinct rows flanking the midvein of each fertile pinnule, positioned roughly halfway between the midvein and the margin. Each sorus is covered by a peltate (umbrella-shaped) indusium that is centrally attached by a short stalk — this peltate form is the hallmark of Polystichum and readily distinguishes it from Dryopteris (reniform indusia) and Athyrium (elongated to J-shaped). The indusium begins pale green, matures to buff-brown, and eventually shrivels to expose the sporangia beneath. Sporangia are long-stalked, leptosporangiate, with an annulus of 12–14 thickened cells that generates the catapult mechanism for spore ejection. Spores are bilateral (monolete), dark brown, 28–35 μm long, with a shallowly verrucate perispore surface. Maturation occurs from July through October in most of the European range; peak dispersal is August–September, when dry air currents carry spores up to several hundred metres from the parent plant. Spore viability is good: fresh spores sown within 3 months of collection give 70–90% germination on sterile moist peat at 15–18°C under indirect light, with green heart-shaped gametophytes (prothalli) appearing in 4–8 weeks. However, many of the named cultivars are partially or fully sterile, or produce spores whose offspring are highly variable and do not resemble the parent — this is why vegetative propagation is preferred for cultivar maintenance. The species also produces vegetative propagules (bulbils) in certain cultivars and wild populations: small plantlets develop on the upper surface of the rachis, typically near the frond base and at pinna junctions, sometimes also on the stipe. These bulbils are miniature plants complete with tiny fronds and root initials. If the frond is pegged down onto moist soil or the rachis is bent to the ground by wind, the bulbils root and establish independent plants — a viviparous habit shared with very few other fern species (Asplenium bulbiferum, some Woodwardia). This rachis-bulbil propagation is the single most important method for maintaining cultivar identity in forms like ‘Divisilobum Densum’ and ‘Plumosum Bevis’ that set little or no viable spore.

Comparison with Similar Species

Polystichum setiferum vs Polystichum aculeatum (Hard Shield Fern): The two grow together in many British and European woodlands and are the most frequently confused pair of hardy ferns. P. setiferum has soft-textured, matte, stalked pinnules with a pronounced basal auricle; P. aculeatum has hard, glossy, sessile (unstalked) pinnules that are decurrent onto the rachilla, giving a stiffer, more rigid frond. P. setiferum is arching and graceful; P. aculeatum is more upright and shuttlecock-shaped. P. setiferum tolerates lime and dry shade; P. aculeatum prefers slightly more moisture and neutral to acidic soils. Both are evergreen, both have peltate indusia. Hybridisation between the two produces Polystichum × bicknellii, which is intermediate and partially fertile. P. setiferum vs Polystichum munitum (Western Sword Fern): P. munitum is a Pacific Northwest native with once-pinnate (NOT bipinnate) fronds up to 150 cm, tough leathery texture, and a much more upright habit. It is a larger, coarser plant for USDA zones 6–9 in western North American gardens; P. setiferum is finer, more architectural, and better suited to European and east-coast American conditions. P. setiferum vs Dryopteris filix-mas (Male Fern): Both are common European garden ferns in the same family (Dryopteridaceae), but P. setiferum is evergreen (filix-mas is deciduous), has peltate indusia (filix-mas has reniform ones), has soft arching fronds (filix-mas is stiffer and more erect), and tolerates drier conditions. Dryopteris filix-mas is harder to −35°C but loses its fronds entirely in winter, whereas P. setiferum provides year-round structure down to −20°C. P. setiferum vs Dryopteris affinis (Golden Male Fern): D. affinis is semi-evergreen with a distinctive dark spot at each pinna base (absent in P. setiferum), leathery fronds, and reniform indusia. P. setiferum is softer-textured, more arching, lime-tolerant, and has peltate indusia. Both are excellent garden ferns; P. setiferum is the better choice for dry shade on chalk.

Reproduction & Propagation

Three methods: division, rachis bulbils, and spores. Division is the simplest for garden-scale increase. In March or early April, lift a mature crown (3+ years old, 5+ fronds), wash the rhizome clean, and cut vertically through the woody caudex with a sharp serrated knife. Each division must carry at least 2–3 growing points and a healthy fan of roots. Pot into 2–3 litre containers of 50:50 loam-based compost and leaf mould, water well, and keep in deep shade for 6–8 weeks until new fronds appear. Division success rate is 80–90% if done before croziers have unfurled. Rachis bulbils are the preferred method for named cultivars. Many P. setiferum cultivars (and some wild plants) produce small plantlets along the upper surface of the rachis, typically at pinna junctions. In late summer or early autumn, cut a frond bearing well-developed bulbils (each should have 1–2 tiny fronds and visible root initials), lay it flat on a tray of moist 50:50 peat-free coir and perlite, and pin the rachis down with wire staples so that the bulbils are in contact with the surface. Cover with a propagator lid or clear plastic bag to maintain 80% humidity. Keep at 12–18°C in bright indirect light. Roots develop in 4–6 weeks; pot individually when the first true frond exceeds 3 cm. This method produces plants genetically identical to the parent — essential for maintaining cultivar integrity. Spore propagation yields genetically diverse offspring and is valuable for raising the species type or for exploring new variation. Collect ripe spores in August–September from fertile pinnae with brown peltate indusia (if indusia are still pale green, the spores are not yet mature). Dry the cut pinnae on clean white paper inside a folded envelope for 48 hours; the spores fall as a fine dark brown dust. Sow thinly onto sterilised peat-free compost (microwave damp compost for 3 minutes) in a sealed clear plastic box at 15–18°C under bright indirect light. Green heart-shaped gametophytes (prothalli) appear in 4–8 weeks; sporophytes emerge from fertilised archegonia after a further 8–16 weeks. Prick out at the 1–2 frond stage into individual cells. Spore-raised plants reach garden-plantable size (15–20 cm fronds) in 12–18 months from sowing. Important: spore offspring from cultivars will be highly variable and almost never resemble the parent form — use bulbils or division for cultivar propagation.

Cultivation & Substrate

Plant Polystichum setiferum in any reasonable garden soil enriched with leaf mould or well-rotted compost, in partial to full shade. The species tolerates a wider range of conditions than almost any other hardy fern: it accepts acid soils (pH 5.5) through to mildly alkaline (pH 7.0, occasionally 7.5 on chalk), copes with dry shade under deciduous trees where most ferns wilt, and survives winter lows to −20°C without protection. The key to success is drainage: P. setiferum resents waterlogged soil more than drought, and in heavy clay the addition of 20–30% coarse grit or leaf mould at planting is essential. North-facing and east-facing borders are ideal; full afternoon sun in zones 8–9 will scorch fronds within a fortnight. Space plants 60–80 cm apart for a naturalistic drift that fills in within two growing seasons. The crown must sit at soil level with the growing point and the dense rosette of scale-covered stipe bases visible — burying the crown even 2–3 cm invites rot. Apply 3–5 cm of leaf mould or composted bark as mulch each spring, pulling it 5 cm back from the crown centre. This is an evergreen fern in mild climates: do NOT cut the fronds back in autumn as they protect the crown through winter and provide year-round structure. In late March or early April, when new croziers begin to emerge from the crown centre, cut the previous year’s fronds back to 5 cm stubs to make room. Feeding is minimal: a single spring topdressing of bone meal (50 g per plant) or a liquid seaweed drench in April suffices. Nitrogen-heavy feeds produce rank soft growth prone to slug damage. Container culture is possible in 10–15 litre pots of John Innes No 2 mixed with 30% leaf mould, but pots require winter protection in zone 6 (wrap with bubble wrap or plunge in a border) because root-zone freezing kills potted ferns that would survive the same temperature in open ground. The species self-seeds freely in favourable conditions: look for tiny prothalli and sporophytes on damp brickwork, between paving slabs, and on the mossy surfaces of old walls.

Common Mistakes to Avoid

The most damaging mistake is cutting back the evergreen fronds in autumn. Unlike deciduous Dryopteris, P. setiferum retains its fronds through winter — they insulate the crown, protect the dormant croziers, and continue photosynthesising on mild winter days. Removing them in October or November exposes the crown to frost damage and reduces spring vigour by 30–40%. Cut back only in late March when new croziers are visibly unfurling. The second error is planting in waterlogged soil. Despite tolerating drought, P. setiferum cannot tolerate standing water around the rhizome; prolonged saturation causes crown rot (Pythium, Phytophthora) that kills within a single season. Heavy clay needs 20–30% grit amendment. Third: confusing P. setiferum with P. aculeatum (Hard Shield Fern). The two grow side by side in many British woodlands. P. aculeatum has sessile (unstalked), hard-textured, glossy pinnules that are decurrent onto the rachilla; P. setiferum has stalked, soft-textured, matte pinnules with the diagnostic basal ‘thumb’. Planting P. aculeatum expecting the arching grace of P. setiferum leads to disappointment — aculeatum is stiffly upright. Fourth: expecting cultivar-true offspring from spores. Most P. setiferum cultivars produce genetically variable spore offspring that bear little resemblance to the parent. Cultivars must be propagated by division or by rachis bulbils for true-to-type plants. Fifth: over-dividing small or young plants. A P. setiferum crown needs at least 3–4 growing points per division; a single-point division has a 50% failure rate. Sixth: planting too deep. The crown must sit at or slightly above soil level. Even 2 cm of soil over the growing point retains moisture against the bud scales and promotes fungal rot. Seventh: mulching directly onto the crown rather than in a ring around it.

Seasonal Considerations

January: Evergreen fronds provide winter structure. Leave them alone. In zone 6, verify that crown mulch is intact; add a loose layer of dry leaves if winds have blown it away. February: Still quiet. Check crown for frost-heave and re-firm any plants lifted by freeze-thaw cycles. Order new cultivars from specialist nurseries for spring planting. March: New croziers begin to unfurl from the crown centre late in the month. Cut last year’s fronds back to 5 cm stubs with sharp secateurs to make room. Apply 3–5 cm of leaf mould mulch in a ring around the crown, keeping it 5 cm clear of the growing point. April: Croziers expanding rapidly. Protect emerging fronds from slugs with wool pellets or ferric phosphate pellets. Water transplants if spring is dry. Divide established crowns now if needed. May: Fronds reaching full length. The arching habit establishes itself. Keep soil evenly moist. No staking needed. June: Full canopy. Apply a liquid seaweed feed if growth looks pale. Sori beginning to form on upper pinnae. Watch for vine weevil notching on container plants. July: Sporangia ripening. Collect fertile pinnae for spore sowing if desired (look for buff-brown peltate indusia). Maintain moisture through summer heat. August: Peak spore dispersal. Detach rachis bulbils from viviparous cultivars and pin onto moist compost in a shaded frame. September: Fronds still full and green. Apply autumn mulch of leaf mould. Drench containers with nematodes (Steinernema kraussei) for vine weevil control. October: Growth slows. Fronds remain evergreen. No cutting back. Reduce watering of container plants but do not let them dry out completely. November: Fronds providing winter structure and crown protection. Wrap containers in bubble wrap or hessian in zone 6 to prevent root-zone freezing. December: Fully dormant growing points, but fronds still green. No intervention. Snow cover is welcome — it insulates the crown.

Diseases & Pests

Polystichum setiferum is one of the most pest-free and disease-resistant garden ferns in cultivation, and serious problems are genuinely rare. The short list of potential issues is worth documenting nonetheless. Vine weevil (Otiorhynchus sulcatus) is the most damaging pest in container culture: the nocturnal adult beetles notch pinnule margins (cosmetic damage only), but their white C-shaped larvae (8–10 mm) feed on roots from July to October and can kill a potted fern by destroying the entire root system. Biological control with entomopathogenic nematodes — Steinernema kraussei drenched into the compost in September at 12–14°C — is effective. Open-ground plants are rarely affected because predatory ground beetles and soil conditions suppress larval populations. Slugs and snails occasionally damage emerging croziers in April, but the tough mature fronds are largely ignored. Ferric phosphate pellets or wool pellet barriers protect new growth. Rust — Milesia polystichi, an obligate parasitic fungus in the Pucciniastraceae — can produce small orange pustules on the undersides of pinnules in persistently wet springs. It is rarely serious enough to require treatment; remove and destroy heavily affected fronds and improve air circulation. Crown rot (Pythium spp., Phytophthora spp.) occurs only in waterlogged or poorly drained soils, particularly in compacted container compost where drainage holes have blocked. The diagnostic sign is a blackened, mushy rhizome base and sudden collapse of the entire crown. Prevention is the only cure: ensure free drainage at planting. Foliar nematodes (Aphelenchoides fragariae) occasionally cause angular brown patches between pinnule veins in warm wet autumns; affected fronds should be removed and burned. No chemical treatment is needed for any of these problems in normal garden conditions.

Indoor Growing & Terrariums

Polystichum setiferum is NOT recommended as a permanent houseplant. Although it is evergreen and superficially attractive for indoor use, the species requires outdoor conditions: seasonal temperature variation, natural air movement, and winter cold (at least several weeks below 10°C) for long-term crown health. In a centrally heated room at 18–22°C year-round, the plant produces progressively weaker fronds, suffers from low humidity and stagnant air, and typically declines to death within 2–3 years. The only viable indoor use is temporary display in a cool, well-ventilated space: an unheated conservatory, a cold porch, or a north-facing hallway where winter temperatures drop to 5–12°C. In such conditions the plant can survive indefinitely, provided it receives bright indirect light (no direct sun), consistent moisture, and monthly liquid seaweed feed during the growing season. Container size should be 10–15 litres minimum for a mature plant. For permanent indoor ferns, choose Nephrolepis exaltata (Boston Fern), Adiantum raddianum (Maidenhair), Asplenium nidus (Bird’s Nest Fern) or Pteris cretica — all subtropical to tropical species that thrive in the constant warmth and humidity of a living room. Polystichum setiferum belongs in the garden, where it becomes a permanent, virtually indestructible feature for decades.

Terrarium Setup

Too large for most terrariums. A mature P. setiferum produces arching fronds 60–120 cm long and needs outdoor winter cold for long-term health, making it unsuitable for enclosed glass containers. However, miniature cultivars and juvenile plantlets offer limited possibilities. Rachis bulbils detached from cultivars like ‘Plumosum Bevis’ or ‘Divisilobum Densum’ can be grown temporarily in large open terrariums (minimum 40 cm tall) on a substrate of 50% peat-free coir and 50% perlite topped with live sphagnum moss. The compact cultivar ‘Congestum’ stays under 30 cm and could survive 1–2 years in a large Wardian case at 10–16°C with good ventilation. Keep humidity at 70–80%, provide bright indirect light (no direct sun), and ensure the substrate drains freely — stagnant water at the rhizome base is fatal. Realistically, though, P. setiferum is a garden fern and any terrarium use is a temporary display rather than a permanent home. For an evergreen fern that genuinely thrives in a terrarium, choose Asplenium nidus, Nephrolepis cordifolia ‘Duffii’, or a small Selaginella.

Landscape & Garden Use

Polystichum setiferum 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

IUCN Red List: Least Concern (LC). Polystichum setiferum is common throughout its western European and North African range, with stable or increasing populations in most countries. It is not listed on any CITES appendix, not included in the EU Habitats Directive annexes, and not considered nationally threatened in any European country. In the United Kingdom it is a widespread native protected only by the general provisions of the Wildlife and Countryside Act 1981 (section 13: offence to uproot any wild plant without landowner consent), with no Schedule 8 special protection needed. Local declines from Victorian over-collection in southern England were temporary; the species has fully recolonised accessible habitats since the early 20th century. The genuine conservation concern lies not with the species itself but with its rare cultivars. Many Victorian cultivars exist as single clones maintained by a handful of specialist growers. If the last plant dies or a collection is abandoned, that cultivar is lost forever — there is no seed bank, no spore bank, and no way to recreate a specific sport from scratch. Several National Collections under the UK National Council for the Conservation of Plants and Gardens (NCCPG, now Plant Heritage) maintain curated holdings of P. setiferum cultivars: the Fibrex Nurseries collection (Warwickshire) holds approximately 50 named forms, and the RHS garden at Wisley (Surrey) maintains reference plantings. Martin Rickard’s personal collection in the Welsh Borders is among the most comprehensive. International exchange of cultivar material between these holders and American collections ( Fancy Fronds nursery, Washington State) provides a degree of backup, but the overall situation remains fragile for the rarest forms.

Collector Notes

This is the collector’s fern — no other hardy fern species offers remotely comparable cultivar diversity. Over 300 forms were named between 1850 and 1920, of which approximately 50–60 survive in specialist collections today. The principal cultivar groups are as follows. The ‘Divisilobum’ group: multi-divided forms where bipinnate architecture is pushed to tripinnate or quadripinnate, producing fronds of extraordinary lace-like fineness. ‘Divisilobum Densum’ is the most widely grown — a dense, heavily divided form, 50–70 cm, with overlapping pinnulets. ‘Divisilobum Iveryanum’ is sparser and more open. The group contains 20+ named clones, many propagated solely by bulbils. The ‘Plumosum’ group: plumose forms with enlarged, overlapping pinnules that give a feathery plume-like texture. ‘Plumosum Bevis’ (found by Mr Bevis in Dorset c. 1876) is widely regarded as the most beautiful cultivar of any hardy fern species — bipinnate with broad, overlapping, almost translucent pinnules that billow like green silk. It is sterile and propagated only by bulbils and division, making large plants expensive. ‘Plumosum Grande’ and ‘Plumosum Green’ are related selections. The ‘Congestum’ group: compact forms with pinnae so compressed and overlapping that the frond appears congested and three-dimensional. ‘Congestum’ reaches only 25–35 cm, making it the best P. setiferum for small gardens and troughs. The ‘Cristatum’ group: crested forms with forked or fan-shaped frond tips and pinna tips. The ‘Proliferum’ group: forms bearing abundant rachis bulbils (viviparous), valuable for easy propagation. ‘Herrenhausen’ is a modern German selection: compact (40–60 cm), congested, neat, with excellent garden performance and RHS AGM — the best choice for gardeners who want a single reliable cultivar. ‘Pulcherrimum’ is a Victorian name for quadripinnate, very finely divided forms intermediate between Divisilobum and Plumosum. Specialist nurseries carrying good collections include Fibrex Nurseries (UK, holds a National Collection), Fancy Fronds (US, Pacific Northwest), and Crug Farm (UK, Welsh collections). The RHS Wisley garden maintains reference plantings. For identification: the key species-level characters are stalked pinnules with a basal ‘thumb’ (auricle), soft texture, pale brown stipe scales, peltate indusia, and 2n = 82.

Ethnobotany & Cultural Significance

The cultural history of Polystichum setiferum is inseparable from the Victorian pteridomania — the fern craze that swept Britain from roughly 1850 to 1890 and made fern-collecting a respectable pastime for all classes. P. setiferum, with its extraordinary morphological variability, was the species at the centre of the mania. Hedgerow-hunting parties scoured Devon, Dorset, Somerset and the Welsh borders for ‘sports’ — aberrant wild plants with crested, plumose, congested or multi-divided fronds — and a good find could fetch prices equivalent to a working man’s monthly wage. Edward Joseph Lowe (1825–1900), a Nottinghamshire naturalist and fellow of the Royal Society, published the definitive illustrated catalogues: Ferns, British and Exotic (8 vols, 1856–1860) and Our Native Ferns (2 vols, 1867–1869), with detailed chromolithographic plates of P. setiferum cultivars that remain the primary references today. Charles Thomas Druery (1843–1917), a City of London clerk turned pteridological authority, served as secretary of the British Pteridological Society and editor of the British Fern Gazette, and did more than anyone to systematise cultivar nomenclature and promote fern hybridisation. The Stansfield nursery in Southport, Lancashire, was the commercial hub: Robert Stansfield and his son James propagated, named and sold P. setiferum cultivars by the hundred, and their handwritten catalogues from the 1880s–1900s are collector’s items. The craze had a dark ecological side: popular sites were stripped of wild ferns, and several authors noted the local extinction of unusual forms within years of their discovery. The backlash against pteridophyte over-collection contributed to early conservation sentiment that eventually fed into the Wildlife and Countryside Act of 1981. In the 20th century, Reginald Kaye (Hardy Ferns, 1968) rescued many cultivars from near-extinction, growing them at his Silverdale nursery in Lancashire. Jimmy Dyce continued the work from the 1970s through the 1990s, personally maintaining some 40 P. setiferum cultivars. Beyond Britain, the species has no significant ethnobotanical or medicinal history — unlike Dryopteris filix-mas (the Male Fern, used as an anthelmintic for 2 000+ years), P. setiferum contains no known pharmacologically active compounds and was not recorded in European herbals or folk medicine.

Frequently Asked Questions