Tropical Adderstongue: Hawaii’s Mysterious Native Fern
Meet the tropical adderstongue (Ophioglossum concinnum), one of Hawaii’s most intriguing native ferns. This little-known perennial belongs to the ancient adder’s-tongue fern family and offers a unique addition to native Hawaiian gardens for those lucky enough to find it.
What Makes Tropical Adderstongue Special
Unlike the showy ferns you might be familiar with, tropical adderstongue is delightfully understated. This small herbaceous fern produces simple, tongue-like fronds topped with distinctive fertile spikes that give the plant its common name. As a forb, it lacks woody tissue and keeps its growing points at or below ground level, making it a perfect low-growing addition to shaded garden spaces.
Where You’ll Find It Growing Wild
Tropical adderstongue is endemic to the Hawaiian Islands, meaning it grows naturally nowhere else on Earth. This special fern calls Hawaii home exclusively, making it a true treasure of the island’s native flora.
Important Conservation Note
Here’s something crucial to know: tropical adderstongue has a global conservation status of S2Q, indicating it’s quite rare and needs our protection. If you’re interested in growing this native Hawaiian fern, please only source it from reputable native plant nurseries that propagate plants responsibly. Never collect plants from the wild, as this threatens already vulnerable populations.
Perfect Gardens for Tropical Adderstongue
This charming fern thrives in:
- Native Hawaiian restoration gardens
- Shaded woodland gardens
- Naturalistic landscapes that mimic native ecosystems
- Understory plantings beneath larger native trees
Growing Conditions and Care
Tropical adderstongue prefers the gentle conditions of its native Hawaiian habitat. Here’s what it needs to thrive:
- Light: Filtered shade to deep shade – avoid direct sunlight
- Soil: Moist, well-draining soil that doesn’t become waterlogged
- Climate: USDA hardiness zones 10-12 (tropical climates only)
- Moisture: Consistent humidity and regular watering
Planting and Care Tips
Growing tropical adderstongue successfully requires patience and attention to its native habitat preferences:
- Plant in a protected, shaded location that mimics forest understory conditions
- Maintain consistent soil moisture without overwatering
- Provide good air circulation while protecting from strong winds
- Mulch around plants to help retain moisture and suppress weeds
- Be patient – like many native ferns, growth can be slow but rewarding
Wildlife and Ecosystem Benefits
While tropical adderstongue doesn’t produce flowers for pollinators (ferns reproduce through spores, not seeds), it plays an important role in Hawaii’s native ecosystems. As part of the understory plant community, it helps create habitat complexity that supports native insects and provides ground cover that prevents erosion.
The Bottom Line
Tropical adderstongue is a wonderful choice for gardeners in tropical climates who want to support Hawaii’s native plant heritage. Just remember to source plants responsibly due to its rare status. While it may not be the showiest plant in your garden, this humble fern connects you to Hawaii’s unique natural history and supports conservation efforts for the island’s irreplaceable native flora.
If you’re not in Hawaii’s tropical climate zones, consider supporting native plant conservation in your own region by choosing locally native ferns and understory plants instead.
