Prince Of Wales Feather

Botanical name: Leptopteris superba
Synonyms: Todea superba, Osmunda superba
Common name(s): Prince of Wales feather, crepe fern, crape fern, heruheru

About
Leptopteris superba is a spectacular large terrestrial fern endemic to New Zealand. It is renowned for its exceptionally delicate, translucent, dark emerald-green fronds, which have a soft, feathery or almost velvet-like appearance. The ultimate frond segments are turned upward at approximately 90° to the plane of the frond, producing a distinctive three-dimensional texture resembling the pile of a carpet. Plants develop from a short erect rhizome that can eventually form a woody trunk up to approximately 1 m tall. It is strongly associated with cool, extremely humid forest and is particularly luxuriant in the high-rainfall forests of the western South Island.

Natural habitat
Occurs in lowland to montane forest, extending locally into subalpine scrub. It is most characteristic of cool, deeply shaded and extremely humid forest, particularly on valley floors, alongside streams and in permanently damp or occasionally boggy ground. Typical forest types include southern beech, podocarp and kāmahi forest. It reaches its greatest abundance in high-rainfall districts, particularly on the western side of the South Island’s Main Divide.

Growing environment
Requires cool temperatures, deep shade, consistently high atmospheric humidity and permanently moist, humus-rich soil. Unlike the related Leptopteris hymenophylloides, it has little tolerance of drying, excessive heat or intense sunlight. The root zone should remain cool and moist throughout the year without becoming stagnant. Sheltered forest gullies, damp valley floors and deeply shaded stream margins provide the most suitable conditions.

Endemic distribution
Endemic to New Zealand and occurring in the North Island, South Island and Stewart Island/Rakiura. It has a predominantly southern distribution. In the North Island it is most common in montane forest from around Mt Te Aroha south to Wellington, although isolated northern records are known. In the South Island it is abundant in wet western forests, including Western Nelson and Westland, and also occurs through Sounds–Nelson, Canterbury, Otago, Southland and Fiordland. It is particularly notable around the Marlborough Sounds, Dunedin and the Catlins. Its recorded altitudinal range extends from sea level in Fiordland to approximately 1,600 m in the Takitimu Range.

Height
Fronds are approximately 250–1,000 mm long. The erect rhizome can gradually develop into a woody trunk reaching approximately 1 m tall, giving mature specimens a substantial overall height.

Width
Individual laminae are approximately 60–250 mm wide. Mature crowns can spread considerably wider as numerous long fronds radiate from the erect rhizome.

Flowering
Not applicable. Leptopteris superba is a fern and does not produce flowers.

Fruiting
Not applicable. It reproduces by spores rather than fruits or seeds. Sporangia are scattered individually over the lower surfaces of fertile fronds rather than being arranged into discrete sori.

Uses

• Specialist native fern collections

• Cool, deeply shaded ferneries

• Damp forest gardens

• Shaded stream and watercourse margins

• High-humidity woodland gardens

• Naturalistic native forest plantings

• Conservation and educational collections

• Feature fern for cool, high-rainfall environments

• Suitable for recreating wet New Zealand montane forest habitat

Appearance
Growth habit: A large terrestrial fern developing from a short, erect rhizome. With age, the rhizome may form a woody trunk up to approximately 1 m tall. Numerous large fronds arise from the crown to create a dense, luxuriant and distinctly feathery plant.

Leaves: Fronds are approximately 250–1,000 mm long. Stipes are unusually short in relation to the size of the frond, approximately 15–190 mm long, pale brown and densely covered in soft woolly hairs. Ear-like lobes may occur around the stipe bases.

The lamina is elliptic and approximately 160–980 × 60–250 mm, characteristically tapering toward both the base and apex. It is extremely thin, membranous and translucent, with a rich dark emerald-green colour. The frond surfaces, particularly the costae of the primary and secondary pinnae, are densely woolly hairy.

There are approximately 30–60 pairs of crowded primary pinnae. The longest occur around the middle of the rachis and measure approximately 30–130 × 6–23 mm. The basal pinnae are dramatically reduced, measuring only approximately 1–20 mm long.

Secondary pinnae are approximately 6–11 × 3–5 mm and divided almost to the midrib. The ultimate segments are linear and blunt-tipped. Most distinctively, they bend upward at approximately 90° to the plane of the frond, producing the characteristic soft, fluffy texture.

Flowers: None. Leptopteris superba is a spore-producing fern.

Fruit: None. Sporangia occur scattered across the lower surfaces of fertile pinnae rather than being concentrated into conventional sori. They are mainly confined to the proximal portions of the primary and secondary pinnae and tend to be more abundant toward the central part of the frond.

Ecology
A specialised fern of New Zealand’s coolest and wettest forest environments. Its extremely thin, translucent fronds are adapted to low-light conditions with consistently high atmospheric humidity. The foliage is highly susceptible to excessive heat, intense sunlight and drying, explaining the species’ strong association with sheltered valley floors and wet forest interiors.

Minute spores are dispersed by wind. Leptopteris superba frequently occurs alongside Leptopteris hymenophylloides. Where the two species meet they can naturally hybridise, producing Leptopteris × intermedia.

Associated habitats
Most frequently associated with cool southern beech, podocarp and kāmahi forests. It favours deeply shaded valley floors, damp gullies, stream margins, boggy forest ground and other sites where atmospheric and soil moisture remain consistently high. In wetter districts it may form a conspicuous component of the forest understory alongside mosses, liverworts, filmy ferns and other moisture-dependent native ferns.

Within Nelson–Tasman it occurs in Western Nelson and Sounds–Nelson, particularly in wetter forest environments where cool temperatures, shelter and high humidity are maintained.

How to grow
A challenging fern best suited to specialist cultivation. Plant in deep shade in a cool, sheltered and consistently humid position. Soil should be deep, rich in humus and organic matter, moisture-retentive but adequately aerated.

Plants must never be allowed to dry out. Maintain consistent moisture around the root system throughout the year and protect the foliage from direct sunlight, hot temperatures and drying winds. A naturally cool south-facing gully, sheltered stream margin or purpose-built shaded fernery offers the best chance of success.

Mulching with leaf litter can help maintain cool soil temperatures and high root-zone humidity. Even with suitable care, cultivation can be difficult, and plants are considerably less forgiving than Leptopteris hymenophylloides.

Propagation
Propagation is principally from spores. Mature spores can be collected from fertile fronds and sown onto a sterile, moist, humus-rich medium under very high humidity. Development from spore to established sporophyte is slow and requires careful control of moisture, temperature and light.

Young plants are particularly vulnerable to drying and should remain in consistently humid, shaded conditions throughout establishment. Because of the species’ demanding environmental requirements, propagation and cultivation are generally best undertaken by experienced fern growers.

Cultural use
The name heruheru is associated with this and other native ferns in te reo Māori. Specific traditional uses attributable solely to Leptopteris superba are not well documented, and historical references to heruheru may encompass more than one fern species. Its contemporary importance lies particularly in its ecological, botanical and horticultural significance as one of New Zealand’s most distinctive forest ferns.

Garden value
An exceptional but demanding native fern. Few New Zealand species can match the luxuriant appearance of a mature Leptopteris superba, with its long, translucent emerald-green fronds and unusual upright ultimate segments creating an extraordinarily soft, feathery texture.

It is most suitable for specialist ferneries, cool shaded gullies and naturally wet forest gardens where humidity remains high throughout the year. For Nelson–Tasman cultivation, the wetter and cooler environments of western and upland districts are considerably more favourable than hot, dry lowland sites. In suitable conditions it can become a magnificent feature plant, but where reliable shade, cool temperatures and continuous moisture cannot be provided, Leptopteris hymenophylloides is generally the more forgiving garden species.