Introduction & Discovery

Phymatosorus scolopendria, the monarch fern, is one of the most culturally significant and widely cultivated tropical ferns in the world, particularly celebrated in Polynesian cultures where it is known by the Hawaiian name laua'e (also written lauaʻe in modern orthography) and holds a central place in lei-making, ceremonial decoration and traditional ethnobotanical tradition. Native across a vast Old World tropical and subtropical range from West Africa through Asia, Australasia, and the Pacific, the species is one of the ecologically most versatile ferns in cultivation, growing as a terrestrial, lithophytic or epiphytic plant on rock, bark, wood and soil substrates and tolerating a range of light conditions from deep shade to bright indirect light with some direct sun. The common English name monarch fern reflects the stately aspect of the long creeping rhizome with its procession of handsomely cut glossy fronds. Taxonomically the species has drifted among several generic treatments: traditionally placed in Polypodium sensu lato, later moved to Microsorum as segregated from Polypodium, and since Pichi Sermolli's 1973 segregation of Phymatosorus usually placed in that narrower genus on the basis of sunken sori in distinct pits, a feature producing the corresponding bumps on the upper frond surface that inspire both the genus name (from Greek phyma, swelling) and the alternative common name wart fern. The specific epithet scolopendria from the Greek scolopendra (centipede) refers to the long narrow pinnae running in parallel rows down the frond, suggesting the leg arrangement of a centipede. The species' most distinctive feature, however, is its fragrance: dried fronds of P. scolopendria release a sweet vanilla-like scent from coumarin derivatives, and this aroma is central to the plant's use in Polynesian lei, where sprigs of dried laua'e are traditionally mixed with maile (Alyxia oliviformis) and other fragrant plant materials to produce the complex layered scent that distinguishes high-quality Hawaiian ceremonial adornment. In Hawaii the plant is technically an introduction (its native range does not extend naturally to the Hawaiian archipelago) but has been culturally adopted so thoroughly that it functions essentially as a native cultural icon. The plant entered European horticulture in the nineteenth century and has been continuously cultivated in tropical glasshouses and tropical outdoor gardens worldwide ever since, valued for both its ornamental qualities and its evocative Pacific associations.

Discovery & Naming

The species now treated as Phymatosorus scolopendria was first formally described by Burman in his Flora Indica of 1768 as Polypodium scolopendria, based on material from tropical Asia. The specific epithet scolopendria comes from the Greek scolopendra (centipede), referring to the many parallel pinnae arranged along the rachis suggesting a centipede's many legs. Subsequent taxonomic treatments moved the species through a succession of generic placements reflecting evolving concepts of Polypodium, Microsorum and Phymatodes: Polypodium scolopendria L. became Polypodium scolopendrium in some Linnean treatments (a distinct species in Asplenium now, producing considerable historical confusion), Microsorum scolopendria (Burm. f.) Copel. became standard in treatments recognising Microsorum as a broad genus segregated from Polypodium, and Phymatosorus scolopendria (Burm. f.) Pic. Serm. became standard after Pichi Sermolli's 1973 segregation of Phymatosorus from Microsorum on the basis of sunken sori in distinct pits. Recent molecular phylogenetic studies by Schneider, Schuettpelz, Kreier, Janssen and collaborators through the 2000s and 2010s have examined the relationships of Phymatosorus and Microsorum and supported the recognition of Phymatosorus as a monophyletic lineage separable from Microsorum in most analyses. Current treatments vary: some retain Phymatosorus as a distinct genus, others subsume it within a broadly defined Microsorum. In horticulture the plant continues to be encountered under both Phymatosorus scolopendria and Microsorum scolopendria as well as the older Polypodium scolopendria in some references. The naturalisation of the species in Hawaii apparently occurred in the nineteenth or early twentieth century, and the cultural adoption of the plant as laua'e is a relatively recent phenomenon overlaid on pre-existing cultural knowledge of the native Hawaiian fern Microlepia strigosa of the same common name.

Native Range & Distribution Map

Distribution map showing the native range of Phymatosorus scolopendria.

Biology & Frond Morphology

Phymatosorus scolopendria belongs to the genus Phymatosorus in the family Polypodiaceae, producing evergreen, pinnate fronds of firm coriaceous texture, medium to deep green above with a distinctive glossy sheen and paler matte green beneath, arising at intervals of 2 to 5 centimetres along a stout long-creeping rhizome that extends across the substrate producing loose colonies rather than tight crowns. mature fronds typically measure 30 to 70 centimetres long and 15 to 30 centimetres wide, bearing 5 to 12 pairs of narrow lanceolate pinnae plus a well-developed terminal pinna. pinnae are 8 to 20 centimetres long and 1.5 to 3.5 centimetres wide, with entire to slightly undulate margins and acuminate tips, joined to the rachis by a broadly decurrent base that may continue as a narrow wing along the rachis. the overall aspect is more delicate and refined than the coarser sister species p. grossus. stipes are pale green to tan, 10 to 25 centimetres long, firmly attached to the rhizome by a distinct articulation. rhizome is 3 to 6 millimetres in diameter, densely clothed in dark lanceolate scales that become sparse on older portions. dried fronds emit a characteristic sweet vanilla-like fragrance from coumarin compounds, the feature that gives the species its central cultural significance in polynesian lei tradition. 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 Phymatosorus scolopendria 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 Phymatosorus scolopendria 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.

Common Mistakes to Avoid

Several recurring errors limit success with P. scolopendria. Burying the rhizome beneath substrate is the most frequent structural mistake; the rhizome creeps on the substrate surface with roots penetrating below, and burying it invites rot. Plant with the rhizome exposed. Exposure to frost or sustained temperatures below 10 degrees Celsius damages or kills plants; outdoor culture is restricted to zones 10 and warmer. Waterlogging is fatal; the plant requires free-draining substrate and tolerates brief drying better than sustained wetness. Using dense heavy substrate (fine peat, ordinary garden soil) produces poor root function and decline; use free-draining epiphyte mixes. Placement in direct sun through south or west windows in dry indoor conditions scorches fronds; use bright indirect light. Attempting to grow as a conventional deep-potted houseplant restricts the creeping habit; use shallow wide pots, hanging baskets or mounts. Failing to allow for the natural spreading habit leads to overcrowding in small containers within 2 to 3 years; repot into progressively larger supports or divide to maintain. Confusing the plant with Microlepia strigosa (the true native Hawaiian laua'e) can occur in Hawaiian horticultural contexts where both plants may be labelled laua'e; examine frond division (P. scolopendria is pinnate with sunken sori, M. strigosa is finely bipinnate to tripinnate with small marginal indusia) to distinguish. Importing wild-collected material from outside the native range without phytosanitary compliance may introduce pests or pathogens; use reputable nursery stock. In Hawaii and other locations where the plant is an invasive non-native, consider the ecological implications before planting in landscapes adjacent to native forest.

Seasonal Considerations

In tropical outdoor cultivation the plant follows a seasonal rhythm driven largely by wet- and dry-season rainfall rather than temperature, with growth continuing year-round. Maintain consistent watering during any dry season and allow natural rainfall to dominate during the wet season. In temperate indoor and conservatory culture a modest seasonal pattern improves performance. Spring from March through May is the period of greatest new frond production; increase watering, resume monthly feeding at quarter to half strength, and consider repotting or division. Summer from June through August brings maximum growth rates; maintain consistent watering, feeding and humidity; watch for spider mite colonisation on indoor plants if household humidity drops. Autumn from September through November brings a modest slowing of growth; reduce watering frequency slightly and cease feeding by mid-October. Spore production is ongoing and mature sori may be collected. Winter from December through February is the indoor rest period; maintain minimum temperatures above 12 degrees Celsius, water less frequently but do not let the substrate dry, withhold fertiliser, avoid cold drafts. The species continues slow frond production through the winter in warm conditions but the pace is reduced. Resume full cultural schedule from late February as days lengthen. Harvesting of fronds for lei or fragrance purposes in Hawaiian cultivation traditionally favours mature well-developed fronds in the warm growing season when the plant is actively producing. For mounted epiphytic plants year-round moisture is required with slight adjustment for seasonal temperature variation; daily misting in warm weather, less frequent in cool conditions.

Diseases & Pests

Common issues affecting Phymatosorus scolopendria 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

Phymatosorus scolopendria 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

Phymatosorus scolopendria 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

Phymatosorus scolopendria is considered globally secure across its extensive Old World tropical range, with populations widespread and often locally abundant in suitable habitat. The species has not been formally evaluated in detail at the species level on the IUCN Red List but would qualify for Least Concern based on extent of occurrence, population size, habitat flexibility and ecological adaptability. No international trade controls apply under CITES. The plant occupies a sufficient range of primary, secondary and anthropogenic habitats across its Old World range that population persistence is essentially secure. In Hawaii and parts of the Pacific where the species is an introduction or naturalisation, it is considered an invasive plant in some conservation contexts owing to its capacity to establish in native forest and outcompete native understorey vegetation in some settings; this distinction is important in the Hawaiian conservation context where the cultural plant laua'e is simultaneously cherished and ecologically problematic. In some Hawaiian National Park and Nature Conservancy management areas the species is actively controlled or removed as a non-native invasive despite its cultural status. This nuanced situation is unusual: the plant is globally secure as a species, culturally significant in Polynesia as an adopted cultural element, and ecologically problematic as a Hawaiian invasive all at once. In the species' native Old World tropical range no conservation concerns apply. Commercial horticultural supply is entirely from nursery stock; wild collection is not a concern. Climate change effects on the species' range are modest owing to ecological flexibility.

Collector Notes

For collectors of tropical Polypodiaceae and Polynesian cultural plants, P. scolopendria is an essential acquisition and a reliable long-term specimen. The plant is widely available in the tropical fern nursery trade and in well-stocked tropical houseplant retailers worldwide. Specialist suppliers in Europe include Farnwerk in Germany, Dutch and Belgian tropical plant nurseries, and various UK tropical plant specialists; in North America Glasshouse Works, Asiatica Nursery, Black Jungle Terrarium Supply, and various tropical houseplant mail-order sources stock the species regularly. In Hawaii laua'e is ubiquitous in the local nursery trade and is gathered from naturalised populations for lei and ornamental use. No significant named cultivars are widely recognised in commerce, though informal selections with somewhat varied pinna shape, frond size or fragrance intensity circulate among Hawaiian lei makers and specialist tropical gardeners. Material of distinct wild provenance from particular African, Asian or Pacific localities is occasionally available through botanical garden exchange networks and specialist tropical fern society connections. The plant ages gracefully over decades in good culture and can be trained into spectacular mounted displays or hanging basket specimens of impressive size. Notable mature specimens in public collections include the tropical fern displays at the Royal Botanic Gardens Kew, Fairchild Tropical Botanic Garden, Hawaii Tropical Botanical Garden, Lyon Arboretum, Foster Botanical Garden in Honolulu, Singapore Botanic Gardens, Bogor Botanic Garden, and numerous other tropical and Pacific collections. For Hawaiian cultural practitioners the plant is a working tool of the traditional lei arts rather than solely an ornamental.

Ethnobotany & Cultural Significance

P. scolopendria holds an exceptionally prominent ethnobotanical position in Polynesian cultures, particularly Hawaiian culture, where it is known as laua'e and serves central functions in traditional lei-making, ceremonial decoration, and scented material production. The dried fronds of laua'e contain coumarin and related phenylpropanoid compounds that release a characteristic sweet vanilla-like fragrance when the foliage is dried or crushed, and this aroma is one of the signature scents of Hawaiian cultural material. Sprigs of dried laua'e are combined with maile (Alyxia oliviformis), palapalai (Microlepia strigosa), and other fragrant plant materials in the construction of high-status lei for hula performance, ceremonial presentation, and personal adornment. The plant is a staple component of the traditional Hawaiian floral and scent culture, and its fragrance is considered emblematic of the islands by residents and visitors alike. In modern Hawaii laua'e is both cultivated in private gardens for lei production and gathered from naturalised wild populations. The distinction between the indigenous Hawaiian laua'e (Microlepia strigosa, a different fern altogether) and the introduced but culturally adopted laua'e (P. scolopendria) is a matter of ongoing cultural and scientific discussion, as the name has been applied to both plants and many modern Hawaiian practitioners use the introduced species primarily. Beyond Hawaii the species has cultural and traditional medicinal uses in various parts of Polynesia, Melanesia and Southeast Asia for decorative, ceremonial and folk-medical purposes, though none equal the prominence of the Hawaiian tradition. In Africa and Asia the species has minor local uses in traditional medicine for poultices and tonics. In Western horticulture since the nineteenth century the species has been valued primarily as an ornamental, with its cultural Polynesian associations adding interest for collectors and tropical garden designers.

Frequently Asked Questions