Thorny Popolo: A Critically Endangered Hawaiian Native Worth Protecting
Meet the thorny popolo (Solanum incompletum), a remarkable Hawaiian native plant that’s fighting for survival in the wild. This perennial shrub holds a special place in Hawaii’s botanical heritage, but it’s also one of the islands’ most endangered plant species. If you’re passionate about native Hawaiian plants and conservation, this thorny beauty might just capture your heart—though growing it comes with important responsibilities.
What Makes Thorny Popolo Special?
Thorny popolo is a multi-stemmed woody shrub that typically grows less than 13-16 feet tall, though it can vary depending on growing conditions. True to its name, this plant sports thorny stems that give it character and help protect it from browsing animals. The plant produces small, delicate flowers that range from white to pale purple, followed by dark berries that add visual interest throughout the growing season.
You might also encounter this plant under its scientific synonyms: Solanum haleakalaense H. St. John, Solanum incompletum var. glabratum, or Solanum incompletum var. mauiense—all names that reflect its complex taxonomic history and regional variations across the Hawaiian islands.
Where Does Thorny Popolo Come From?
This shrub is endemic to Hawaii, meaning it exists naturally nowhere else on Earth. Historically, thorny popolo grew across several Hawaiian islands, typically thriving on volcanic slopes and in areas with well-draining soils.
The Conservation Reality: Why This Plant Needs Our Help
Here’s the sobering truth: Thorny popolo carries a Global Conservation Status of S1, which means it’s critically imperiled. With typically five or fewer occurrences and very few remaining individuals (fewer than 1,000), this species is classified as Endangered in the United States. This isn’t just another rare plant—it’s teetering on the brink of extinction.
If you’re considering growing thorny popolo, this rarity status comes with serious responsibilities. You should only obtain plants or seeds through legitimate conservation programs, botanical institutions, or certified native plant suppliers who can guarantee their material is ethically and legally sourced.
Growing Thorny Popolo: For the Dedicated Conservationist
Successfully growing thorny popolo requires understanding its natural habitat preferences. This plant thrives in USDA hardiness zones 10-11, making it suitable only for tropical and subtropical climates or greenhouse cultivation in cooler areas.
Ideal Growing Conditions
- Well-draining volcanic or sandy soils
- Partial shade to full sun exposure
- Consistent moisture without waterlogging
- Protection from strong winds
- Warm temperatures year-round
Care Tips for Success
- Plant in spring when temperatures are consistently warm
- Mulch around the base to retain moisture and suppress weeds
- Water regularly during establishment, then reduce frequency once established
- Prune carefully around thorns to maintain shape
- Monitor for pests, though native plants typically have fewer issues
The Role of Thorny Popolo in Your Garden
This isn’t a plant for every garden—and that’s exactly the point. Thorny popolo serves a specialized role in native Hawaiian restoration projects, botanical collections, and conservation gardens. Its flowers provide nectar for native Hawaiian pollinators, while its berries can support local bird populations when the plant is mature enough to fruit.
If you’re creating a native Hawaiian landscape or participating in conservation efforts, thorny popolo can serve as a conversation starter about plant conservation and the importance of protecting endemic species.
Should You Grow Thorny Popolo?
The answer depends entirely on your commitment to conservation and your access to legitimate plant sources. This isn’t a casual gardening choice—it’s a conservation commitment. You should only consider growing thorny popolo if you:
- Can source plants or seeds through legitimate conservation channels
- Live in an appropriate climate (zones 10-11) or have greenhouse facilities
- Are committed to proper care and potentially participating in seed collection or propagation efforts
- Understand the plant’s conservation significance and can share its story with others
A Plant Worth Protecting
Thorny popolo represents more than just another garden plant—it’s a living piece of Hawaiian natural heritage that desperately needs our protection. While not everyone can or should grow this endangered species, we can all appreciate its beauty and support conservation efforts to ensure it doesn’t disappear forever.
If growing thorny popolo isn’t right for your situation, consider supporting local botanical gardens, native plant societies, or conservation organizations working to protect Hawaii’s endangered flora. Every effort counts when it comes to saving species on the brink of extinction.
