Coprosma Acutifolia
Coprosma acutifolia
Coprosma acutifolia is a shrub native to New Zealand, found exclusively on Raoul Island. It can grow up to 12 meters tall, acting as a sub-canopy tree at lower altitudes and a canopy species along ridgelines. Its leaves are typically 60-90 × 20-35 mm, yellow-green, and often mottled with dark green. native shrubs
Plant Description
The plant is also known for its sharp-pointed leaves with a glossy, often dark green hue, and it thrives in coastal regions. The genus name "Coprosma" comes from the Greek words for "dung" and "smell," referring to the genus's foul odor, while "acutifolia" is Latin for "sharp-leaved." The plant produces orange-red, oblong drupes that are 7-8 mm long.
Quick Facts
| Scientific Name | Coprosma acutifolia |
|---|---|
| Height | Up to 12m |
| Spread | Up to 5m |
| Water Needs | Moderate |
| Light | Full sun |
| Frost Tolerance | Moderately frost-hardy |
| Salt Tolerance | High |
| Growth Rate | Moderate |
| Lifespan | Long |
Climate Best Suited to
Coprosma acutifolia is found exclusively on Raoul Island and thrives in coastal regions. It prefers a warm, frost-free environment.
Regional Suitability
| City | Climate Suitability |
|---|---|
| Whangārei | Ideal |
| Auckland | Ideal |
| Hamilton | Ideal |
| Tauranga | Ideal |
| Rotorua | Ideal |
| Gisborne | Ideal |
| New Plymouth | Ideal |
| Napier | Ideal |
| Whanganui | Ideal |
| Palmerston North | Ideal |
| Wellington | Ideal |
| Nelson | Ideal |
| Christchurch | Moderate |
| Dunedin | Moderate |
| Invercargill | Moderate |
Plant Habitat
Coprosma acutifolia is found exclusively on Raoul Island, where it acts as a sub-canopy tree at lower altitudes and a canopy species along ridgelines.
Plant Conservation
Coprosma acutifolia is classified as "Not Threatened". This endemic species is restricted to Raoul Island in the Kermadec Islands, approximately 1,000 kilometres northeast of New Zealand's North Island. While the population appears stable within its limited range, the species faces potential threats from invasive weeds, grazing by introduced mammals, and climate change impacts on its isolated island ecosystem. Conservation efforts focus on habitat protection and monitoring of population trends to ensure the long-term survival of this unique coprosma species.
Growing Requirements
Soil Requirements
Coprosma acutifolia prefers well-drained, fertile soil.
- Prefers well-drained, fertile soil
Light Requirements
This plant thrives in full sun.
- Prefers full sun
Water Requirements
Coprosma acutifolia has moderate water needs.
- Moderate water needs
Planting Guide
Coprosma acutifolia grows well from semi-hardwood cuttings and fresh seeds, making it accessible for cultivation outside its native range. Plant in a warm, frost-free environment with excellent drainage, as this species cannot tolerate waterlogged conditions. Choose a sunny to semi-shaded location protected from strong winds, particularly when plants are young. Space plants 2-3 metres apart to allow for their mature spread. The best planting time is during spring or early autumn when temperatures are moderate and rainfall is adequate. Mulch around the base to retain moisture and suppress weeds, but keep mulch away from the trunk to prevent collar rot.
Ecological Role
The orange-red drupes of Coprosma acutifolia serve as an important food source for native birds on Raoul Island, including endemic subspecies of silvereye and grey warbler. As a key component of the island's forest ecosystem, this coprosma provides both shelter and sustenance for various wildlife species. The plant's dense branching habit creates nesting sites for small birds, while its flowers attract native insects that form part of the island's food web. Through seed dispersal by frugivorous birds, C. acutifolia contributes to forest regeneration and helps maintain the genetic diversity of its populations across suitable habitats on the island.
Uses & Significance
Garden Uses
Coprosma acutifolia is an attractive shrub for coastal gardens. Its glossy green leaves and orange-red berries provide year-round interest.
- Coastal gardens
- Specimen shrub
The genus name "Coprosma" comes from the Greek words for "dung" and "smell," referring to the genus's foul odor.
- Genus name refers to foul odor
Ecological Value
The fruit of Coprosma acutifolia is a food source for native birds.
- Food source for native birds
Landscaping Uses
In a landscaping context, Coprosma acutifolia is an excellent choice for a coastal garden. It can be used as a hedge or as a specimen shrub. Its tolerance of salt spray makes it a very useful plant for seaside locations.
Seasonal Care Calendar
Spring
In spring, new growth will appear. This is a good time to apply a slow-release fertilizer.
- Apply slow-release fertilizer
- Monitor for new growth
Summer
During summer, regular watering is beneficial, especially during dry spells.
- Water regularly
Autumn
In autumn, the fruit will ripen. This is a good time to collect seed for propagation.
- Collect seed
Winter
In winter, the plant is largely dormant. Pruning is generally not required.
- Minimal care required
When to Prune and How Much
Pruning is generally not required for Coprosma acutifolia. However, it can be lightly pruned to maintain its shape.
- Lightly prune to shape
Always use clean, sharp tools for pruning to minimize the risk of disease.
How to Grow Coprosma acutifolia
From Seed
Coprosma acutifolia is easily grown from fresh seed, though this requires patience and attention to detail. The orange-red drupes should be collected in autumn when they are fully ripe and have developed their characteristic glossy appearance. Fresh seed is essential as viability decreases rapidly once dried. To prepare the seed, remove the fleshy outer layer by gently mashing the fruit and washing away the pulp under running water. The small, hard seeds can then be sown immediately in a well-drained seed-raising mix consisting of equal parts sterilized potting mix and perlite or coarse sand. Sow seeds at a depth of approximately 3-5mm and maintain consistent moisture without waterlogging. Germination is typically erratic, with some seeds sprouting within 4-6 weeks while others may take 6-12 months. Maintain temperatures between 15-20°C and provide bright, indirect light. Young seedlings grow slowly initially, developing their characteristic sharp-pointed leaves as they mature. Transplant carefully when plants reach 5-10cm height, as the root system can be delicate.
From Cuttings
Vegetative propagation through semi-hardwood cuttings offers a more reliable method than seed propagation, producing plants identical to the parent. Take cuttings of 8-12cm length from healthy, disease-free branches during late summer or early autumn when growth is semi-mature. Select shoots that are firm but still flexible, avoiding very soft new growth or completely hardened wood. Remove leaves from the bottom half of the cutting and make a clean cut just below a node. Dip the base in rooting hormone containing IBA (indole-3-butyric acid) at 3000-5000ppm concentration. Insert cuttings into a propagation mix of 50% peat moss and 50% perlite, ensuring good drainage while retaining moisture. Maintain humidity using a propagation tent or misting system, keeping temperatures steady at 18-22°C. Provide bright, filtered light but avoid direct sunlight which can stress the cuttings. Root development typically occurs within 6-10 weeks, indicated by new shoot growth. Once well-rooted, gradually acclimatize cuttings to normal growing conditions before transplanting into individual containers.
Pests & Diseases
Coprosma acutifolia is generally a robust, pest and disease-free plant in cultivation, reflecting its adaptation to the harsh conditions of its native Raoul Island environment. However, young plants may occasionally be affected by scale insects or aphids, particularly in greenhouse conditions or when grown in sheltered garden locations. Good air circulation and avoiding overhead watering help prevent fungal issues such as powdery mildew. Root rot can occur in poorly drained soils, making proper drainage essential for plant health. In its natural habitat, the main threats come from browsing by introduced goats and competition from invasive weeds rather than traditional pests or diseases.
Cultural Significance
Coprosma species (including well-known karamū and mingimingi) appear in mātauranga Māori for restoration plantings and, in some species, as minor mahinga kai where ripe berries were occasionally eaten. There are no widely recorded, species-specific traditional uses for Coprosma acutifolia, but as a native shrub it contributes to the health of the ngahere and supports manu through fruiting.
- Genus noted in rongoā and restoration contexts
- Fruiting supports native birds (manu)
- No specific traditional uses documented for this species
Bonus Tip
The name "acutifolia" is Latin for "sharp-leaved," which perfectly describes this plant's distinctive pointed foliage. To distinguish Coprosma acutifolia from similar species, look for its characteristic yellow-green leaves that are often mottled with darker green patches, and note the relatively large size of mature specimens compared to other coprosmas. The sharp-pointed leaves have a glossy upper surface and are arranged in opposite pairs along the stems. When collecting seeds for propagation, wait until the orange-red drupes are fully ripe and soft to the touch, as this ensures the best germination rates.
Related Plants
Explore other native shrubs that share similar characteristics or habitats with Coprosma acutifolia, offering further insights into New Zealand's diverse flora.