Spleenwort Cyanea: A Critically Endangered Hawaiian Treasure
Meet the spleenwort cyanea (Cyanea aspleniifolia), one of Hawaii’s most remarkable—and most threatened—native plants. This stunning shrub is a true botanical gem that deserves our attention, not just for its beauty, but for its precarious place in the natural world.
What Makes Spleenwort Cyanea Special?
The spleenwort cyanea gets its common name from its distinctive leaves that resemble giant fern fronds, specifically those of spleenwort ferns. This perennial shrub is a member of the bellflower family and can grow to impressive heights of 13-16 feet under ideal conditions, though it typically stays smaller in cultivation.
What really sets this plant apart are its spectacular flower spikes. Rising above the deeply lobed foliage, these tall spires showcase tubular flowers that were specifically designed by nature to attract Hawaii’s native honeycreeper birds—a relationship that’s become increasingly rare as both species face extinction pressures.
A Plant in Crisis
Important Conservation Alert: Before we dive into growing this beauty, you need to know that spleenwort cyanea is critically endangered. It holds a Global Conservation Status of S1, meaning it’s at extreme risk of extinction, with typically fewer than 1,000 individuals remaining in the wild. In the United States, it’s officially listed as Endangered.
This means if you’re considering adding this plant to your garden, you must only obtain it from legitimate, responsibly sourced suppliers who are working with conservation programs. Never collect from wild populations.
Where Does It Call Home?
Spleenwort cyanea is endemic to Hawaii, meaning it exists nowhere else on Earth naturally. Within the Hawaiian Islands, it’s found in wet forest environments where it thrives in the understory of native ohia and koa forests.
Garden Role and Landscape Design
If you’re fortunate enough to obtain responsibly sourced plants, spleenwort cyanea makes an extraordinary specimen plant for tropical gardens. Its architectural foliage and impressive flowering display create dramatic focal points, especially when planted in groups.
This shrub works beautifully in:
- Native Hawaiian plant gardens
- Conservation-focused landscapes
- Tropical understory plantings
- Shaded garden borders
- Educational botanical displays
Growing Conditions and Care
Spleenwort cyanea is definitely not a beginner plant—it requires specific conditions to thrive:
Climate: This tropical native only grows in USDA hardiness zones 10-11. It needs consistently warm temperatures and high humidity year-round.
Light Requirements: Provide partial to full shade, mimicking its natural forest understory habitat. Too much direct sunlight can scorch the leaves.
Soil Needs: Well-draining but consistently moist, organic-rich soil is essential. Think forest floor conditions—rich, dark, and never bone dry.
Water Requirements: Consistent moisture is crucial, but avoid waterlogged conditions. This plant appreciates the high humidity of its native cloud forests.
Planting and Care Tips
Growing spleenwort cyanea successfully requires attention to detail:
- Plant in a sheltered location protected from strong winds
- Maintain consistent soil moisture without overwatering
- Provide regular misting to increase humidity around the plant
- Use organic mulch to help retain moisture and provide nutrients
- Avoid fertilizers high in phosphorus, which can harm Hawaiian natives
Supporting Conservation
By growing spleenwort cyanea responsibly, you’re not just adding a unique plant to your garden—you’re participating in conservation efforts. Every cultivated plant represents hope for this species’ survival and can potentially contribute to restoration programs.
Consider connecting with local botanical gardens, native plant societies, or conservation organizations to learn more about supporting Hawaiian plant conservation efforts.
The Bottom Line
Spleenwort cyanea is undoubtedly one of the most spectacular native Hawaiian plants you could grow, but it comes with significant responsibility. Only pursue growing this plant if you can source it responsibly and provide the specialized care it needs. For most gardeners interested in Hawaiian natives, consider starting with less threatened species while supporting conservation efforts for rarities like this one.
Remember: every rare plant we can successfully cultivate and protect represents hope for preserving Hawaii’s unique botanical heritage for future generations.
