<i>Ophioglossum coriaceum</i>(Ophioglossum coriaceum) hero image

Adder's Tongue

Ophioglossum coriaceum

Not specified

This native plant, known as Adder's Tongue (scientific name: Ophioglossum coriaceum ), is a remarkable species endemic to New Zealand. It is characterized by its unique features, ecological role, and cultural significance. This comprehensive guide provides detailed information on its care, propagation, and importance within the New Zealand ecosystem. Understanding this plant contributes to the appreciation of our rich biodiversity and heritage, and supports conservation efforts for Browse All .

<i>Ophioglossum coriaceum</i>(Ophioglossum coriaceum) showing <i>Ophioglossum coriaceum</i>growth habit
Image credit: Adder's Tongue (Ophioglossum coriaceum) - Photo via Wikipedia

Plant Description

Identification and Physical Characteristics

Ophioglossum coriaceum is a small terrestrial fern that typically grows to between 5 and 20 cm in height, though it can reach 25 cm in very wet conditions Discover more about native shrubs. It grows from an erect, cylindrical rhizome with fleshy, orange-brown roots. The fern usually produces only one or two fronds at a time, though mature colonies can form extensive mats through vegetative budding from the roots.Each frond is divided into two distinct parts. The sterile, leafy portion (lamina) is fleshy, leathery, and a bright green to yellow-green colour. It is typically elliptic or ovate in shape, measuring 8-30 mm long. The fertile portion (the sporophore) is an upright, narrow spike that is usually much longer than the leaf, reaching up to 10 cm or more. This spike bears two rows of 3-17 pairs of deeply embedded sporangia (spore cases) that release fine yellow spores when mature. The species name "coriaceum" refers to the leathery, tough quality of the sterile leaf, which helps the plant withstand exposure.

Quick Facts

Ophioglossum coriaceum quick facts
Scientific Name Ophioglossum coriaceum
Height 5-25 cm
Spread Forms colonies 10-30 cm across
Water Needs Moderate to high; likes consistent moisture
Light Full sun to partial shade
Frost Tolerance Very High
Salt Tolerance Moderate
Growth Rate Slow
Lifespan Perennial

Climate Best Suited to

Ophioglossum coriaceum is well adapted to various New Zealand regions.

Regional Suitability

City suitability for Ophioglossum coriaceum
City Climate Suitability
Auckland High
Wellington High
Christchurch Medium

Plant Habitat

Natural Occurrence and Ecology

The habitat of Ophioglossum coriaceum is remarkably diverse. It is found throughout New Zealand, from the Kermadec Islands to the subantarctic. It occurs in lowland, montane, and subalpine zones. Its preferred environments include damp grasslands, forest clearings, the margins of lakes and rivers, and peat bogs. It is also found in more extreme sites such as stable sand dunes, rocky outcrops, and even around geothermal vents where soil temperatures are elevated. It is a specialist of open ground where competition from taller plants is limited by either extreme conditions or recent disturbance.

Growing Requirements

Soil Requirements

Prefers well-draining soil rich in organic matter.

  • Well-drained
  • Loamy

Light Requirements

Grows best in partial to full sun.

  • Full Sun
  • Partial Shade

Water Requirements

Requires regular watering during dry periods.

  • Regular
  • Drought tolerant once established

Planting and Establishing

Establishment Guidance

Plant Ophioglossum coriaceum in a hole twice the width of the root ball.

Proper establishment is key to long-term success. Ensure the planting hole is twice as wide as the root ball and backfill with a mix of native soil and organic compost. Initial watering should be thorough, followed by regular monitoring during the first two growing seasons to ensure the plant becomes well-anchored and resilient to local climate fluctuations.

Ecological Role

Biodiversity and Ecosystem Impact

Provides habitat and food for native fauna.

This species plays a vital role in its local ecosystem, providing essential habitat and food sources for native biodiversity. Its presence supports complex ecological interactions, contributing to the overall health and stability of the environment. By planting this native, you help maintain the intricate web of life that defines New Zealand's unique natural heritage.

Uses & Significance

Garden Uses

Ideal for rock gardens and native borders.

  • Rock gardens
  • Ground cover

Ecological Value

Supports local pollinators.

  • Birds
  • Insects

The versatility of this plant makes it a valuable addition to many New Zealand gardens. Beyond its aesthetic appeal, it offers practical benefits such as soil stabilization and shelter for smaller plants. Its historical and modern uses highlight its enduring importance in both traditional practices and contemporary landscape design, making it a thoughtful choice for any restoration or gardening project.

Landscaping Uses

Adds texture and form to modern landscapes.

In a landscape setting, this plant provides excellent structure and year-round interest. Its unique form and foliage can be used to create focal points or as a cohesive element in a larger native planting scheme. It pairs well with other New Zealand natives, allowing for the creation of diverse and resilient garden environments that reflect the natural beauty of Aotearoa.

Seasonal Care Calendar

Spring

Mulch and apply balanced fertilizer.

  • Fertilize
  • Mulch

Summer

Water deeply during dry spells.

  • Water
  • Check for pests

Autumn

Tidy up any dead foliage.

  • Prune lightly
  • Plant new specimens

Winter

Protect from heavy frosts if necessary.

  • Frost protection

When to Prune and How Much

Minimal pruning required to maintain shape.

  • Remove dead branches

Always use clean, sharp tools.

Regular maintenance through careful pruning ensures the plant remains healthy and maintains its desired shape. Focus on removing dead or diseased wood to promote better air circulation and prevent the spread of pathogens. Proper pruning techniques help the plant direct its energy toward new growth, resulting in a more robust and aesthetically pleasing specimen in your garden.

How to Grow Adder's Tongue

Cultivating Ophioglossum coriaceum ( Ophioglossum coriaceum ) is a rewarding endeavor for any gardener interested in New Zealand's unique flora. This species can be propagated through several methods, each requiring specific conditions to ensure healthy growth and establishment. Successful propagation depends on mimicking the plant's natural environment and providing consistent care during the early stages of development.

From Seed

Propagation from seed is often the most effective way to produce a large number of Ophioglossum coriaceum plants. Seeds should be collected when they are fully mature. Freshly collected seeds generally have higher germination rates than those that have been stored for long periods.

Sow fresh seeds in a seed-raising mix.

  1. Collect seeds
  2. Sow in trays

Keep moist until germination.

From Cuttings

For those wishing to replicate specific characteristics of a parent plant, vegetative propagation via cuttings is the preferred method. This technique ensures that the new plants are genetically identical to the source. Semi-hardwood cuttings taken during the appropriate season usually yield the best results for this species.

Take semi-hardwood cuttings in late summer.

  1. Take cuttings
  2. Use rooting hormone

Additional Methods

Depending on the growth habit of Ophioglossum coriaceum , other methods such as division or layering might also be viable options. Division is particularly suitable for plants that form dense clumps or have spreading root systems, while layering can be used for species with trailing or flexible stems.

Division can be done in early spring.

  1. Divide clumps
  2. Replant immediately

Pests & Diseases

Generally resistant to major pests.

While generally resilient, maintaining optimal growing conditions is the best defense against pests and diseases. Regular monitoring allows for early detection of any issues, which can often be managed through cultural practices or organic interventions. Ensuring good air circulation and appropriate watering will significantly reduce the plant's susceptibility to common environmental stresses and pathogens.

Cultural Significance

The Adder's Tongue fern is part of the rich tapestry of New Zealand's native flora. While specific traditional medicinal uses are not as prominent as for some other ferns, its unique form was certainly noted. Today, it is valued by botanists and indigenous ecologists as a "taonga" of New Zealand's open wetlands and alpine edges, representing the ancient botanical heritage of the land.

  • Traditional medicine
  • Crafts

Bonus Tip

Excellent for low-maintenance gardens.

For an extra boost, consider applying a thin layer of high-quality organic mulch around the base of the plant. This helps retain soil moisture, suppresses weeds, and gradually improves soil structure as it breaks down. This simple step can make a significant difference in the plant's overall vigor and resilience, especially during periods of extreme weather.

Plant Conservation

Conservation Status

Adder's Tongue is currently classified as "Not Threatened." It remains common and widespread, although its small size and tendency to go dormant in dry periods mean it is often under-recorded in botanical surveys. While the species as a whole is secure, localized populations can be threatened by the invasion of aggressive exotic grasses or the drainage of the damp wetland areas it favours. Protecting small, damp open spaces and preventing the complete overgrowth of rock faces by exotic weeds are important for maintaining its presence in more developed landscapes.