<i>Lophomyrtus obcordata</i>(Lophomyrtus obcordata) hero image

Rōhutu

Lophomyrtus obcordata

Not specified

This native plant, known as Rōhutu(scientific name: Lophomyrtus obcordata ), 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>Lophomyrtus obcordata</i>(Lophomyrtus obcordata) showing <i>Lophomyrtus obcordata</i>growth habit
Image credit: Rōhutu ( Lophomyrtus obcordata ) - Photo via Wikipedia

Plant Description

Identification and Physical Characteristics

Rōhutu ( Lophomyrtus obcordata ) is a tall, bushy, broadleaf evergreen shrub or small tree endemic to New Zealand, reaching up to 5-6 meters in height Discover more about native trees. It has a smooth, beige trunk with flaking greyish bark and numerous, erect, and somewhat pubescent branchlets. Its most distinctive feature is its small (5-10 mm long and wide), thick, heart-shaped (obcordate) leaves, which are often notched at the tip. The leaves are typically dark green to grey-green on top and paler underneath. It produces white, solitary, axillary flowers, 6-8 mm in diameter, with numerous stamens, blooming in spring or early summer. These are followed by oval berries, 6-7 mm long, that range in colour from bright red to dark red, and occasionally black or violet. It is typically found in lowland forests, thriving in rich, deep, loamy, and moist soils.

Quick Facts

Lophomyrtus obcordata quick facts
Scientific Name Lophomyrtus obcordata
Height 15-20 m
Spread 3-5 m
Water Needs Moderate
Light Full sun to part shade
Frost Tolerance Moderate
Salt Tolerance Moderate
Growth Rate Medium
Lifespan Long

Climate Best Suited to

Lophomyrtus obcordata is well adapted to various New Zealand regions.

Regional Suitability

City suitability for Lophomyrtus obcordata
City Climate Suitability
Auckland High
Wellington High
Christchurch Medium

Plant Habitat

Natural Occurrence and Ecology

Rōhutu ( Lophomyrtus obcordata ) is endemic to New Zealand, primarily found in coastal and lowland forested habitats, particularly in the eastern North and South Islands. It can also be found in montane forests, though less frequently. This species is occasionally dominant in alluvial forest remnants and often grows in mixed podocarp forests. It prefers rich, deep, loamy, and moist soils, and can also be found on stable sand dunes within forests.

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 Lophomyrtus obcordata 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 Rōhutu

Cultivating Lophomyrtus obcordata ( Lophomyrtus obcordata ) 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 Lophomyrtus obcordata 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 Lophomyrtus obcordata , 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

Lophomyrtus obcordata , also known by its Māori names rōhutu or tutuhi, is a flowering plant endemic to New Zealand. While extensive cultural significance beyond its Māori names is not widely detailed, its endemic status and recognition within Māori language highlight its cultural importance.Endemic to New Zealand:It is found on both the North and South Islands, primarily in coastal and lowland forests, and occasionally in montane areas.Māori Names:It is commonly known as rōhutu or tutuhi, indicating its familiarity and presence in traditional Māori knowledge.Ecological and Horticultural Importance:It is an attractive and hardy shrub, easily propagated, and commonly used in New Zealand nurseries for ornamental or shelter plantings, and sometimes for revegetation projects. Its dense foliage and upright form make it suitable for hedging.Conservation Status: Lophomyrtus obcordata was given a conservation status of "Threatened - Nationally Critical" in 2018 due to threats like myrtle rust (Austropuccinia psidii), which has been recorded in some natural populations. Conservation efforts, including ex-situ conservation through seed banking, are being explored to preserve its genetic variability.

  • 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

Lophomyrtus obcordata , also known by its Māori names rōhutu or tutuhi, is a flowering plant species endemic to New Zealand and is currently facing significant conservation challenges. In 2018, Lophomyrtus obcordata was officially listed as "Threatened" and "Nationally Critical" in New Zealand. It is also categorized as "At Risk - Declining." The most substantial threat to Lophomyrtus obcordata is myrtle rust (Austropuccinia psidii), a fungal disease that rapidly spreads and devastates species within the Myrtaceae family, to which Lophomyrtus obcordata belongs. The rust causes bright yellow spots and can lead to the decline and death of affected plants. It significantly impacts the plant's reproductive success, causing up to 90% of fruits to drop prematurely and potentially leading to functional extinction in certain regions. Other contributing factors to its vulnerability include habitat loss from urban development, agricultural expansion, and deforestation, as well as competition from invasive plant species. Conservation efforts involve relocation and protection in rust-free areas, ex-situ conservation methods like seed banking, and ongoing research and monitoring.