Native Plants

Hawai’i Horsenettle

Solanum sandwicense

USDA symbol: SOSA4

perennial subshrub

Hawaii: native

Meet the Hawai’i horsenettle (Solanum sandwicense), one of the islands’ most endangered native shrubs. This critically imperiled member of the nightshade family represents both the unique beauty of Hawaiian flora and the urgent need for conservation in our gardens. This perennial shrub is a true Hawaiian endemic, meaning it exists ...

Hawai’i Horsenettle may be listed as rare in your area.
Global Conservation Status

Status: S1 | Critically imperiled: Typically 5 or fewer occurrences or under 1,000 remaining individuals.

United States

Status: Endangered | Endangered. In danger of extinction throughout all or a significant portion of its range.

Hawai’i Horsenettle: A Rare Hawaiian Native Worth Protecting

Meet the Hawai’i horsenettle (Solanum sandwicense), one of the islands’ most endangered native shrubs. This critically imperiled member of the nightshade family represents both the unique beauty of Hawaiian flora and the urgent need for conservation in our gardens.

What Makes Hawai’i Horsenettle Special?

This perennial shrub is a true Hawaiian endemic, meaning it exists nowhere else on Earth. Growing as a multi-stemmed woody plant typically reaching 4-5 meters (13-16 feet) in height, Hawai’i horsenettle showcases the distinctive characteristics that make Hawaiian native plants so remarkable. You might also see it referenced by its botanical synonyms, Solanum hillebrandii or Solanum kavaiense, in older botanical literature.

Where Does It Naturally Grow?

Hawai’i horsenettle is found exclusively in the Hawaiian Islands, where it has adapted to the unique volcanic landscapes and tropical climate conditions that define the archipelago.

  • Species observed
  • No observations

A Conservation Priority

Important Conservation Note: Hawai’i horsenettle carries a Global Conservation Status of S1, meaning it’s critically imperiled with typically fewer than 5 occurrences or very few remaining individuals (less than 1,000). It’s also listed as Endangered in the United States. This makes it one of Hawaii’s most at-risk native plants.

Should You Plant Hawai’i Horsenettle?

If you’re passionate about Hawaiian native plant conservation and have access to responsibly sourced material, growing Hawai’i horsenettle can be a meaningful contribution to preservation efforts. However, this isn’t a plant for casual gardeners – it requires specific conditions and should only be grown with plants obtained through legitimate conservation programs or botanical institutions.

Growing Conditions and Care

As a Hawaiian native, this shrub thrives in tropical conditions equivalent to USDA hardiness zones 10-12. It naturally grows in Hawaii’s unique volcanic environments, suggesting it prefers:

  • Well-draining, volcanic-type soils
  • Partial shade to full sun exposure
  • Tropical temperatures year-round
  • Natural rainfall patterns similar to its native habitat

Garden Role and Landscape Use

Due to its endangered status, Hawai’i horsenettle is primarily suited for:

  • Native Hawaiian restoration projects
  • Botanical gardens and educational institutions
  • Specialized conservation collections
  • Research and propagation facilities

This isn’t a plant for typical landscape use, but rather a species that requires dedicated conservation-minded gardening.

Supporting Conservation

Rather than attempting to grow this rare species without proper resources, consider supporting Hawaiian native plant conservation through:

  • Donating to native plant societies and botanical gardens in Hawaii
  • Volunteering with habitat restoration projects
  • Growing other native Hawaiian plants that are less endangered
  • Advocating for native habitat protection

The Bottom Line

Hawai’i horsenettle represents the irreplaceable botanical heritage of the Hawaiian Islands. While most gardeners won’t have the opportunity to grow this critically endangered shrub, understanding its plight helps us appreciate the importance of protecting Hawaii’s unique ecosystems. If you’re in Hawaii and interested in native gardening, connect with local botanical institutions to learn about conservation efforts and discover other native species you can responsibly incorporate into your landscape.

Every native plant we lose diminishes the natural world’s diversity, making species like Hawai’i horsenettle precious reminders of what we’re working to preserve for future generations.

Solanum sandwicense is also known as...

Often we refer to plants by their common names. When shopping for plants the scientific name is the best way to positively identify the plant species you desire. But some plants have more than one name! While it doesn't happen often, nurseries might display one name while you're searching for another. Solanum sandwicense is also known as:

Solanum hillebrandii | USDA symbol: SOHI2
Solanum kavaiense | USDA symbol: SOKA

Why do some plants have more than one name? Over time plant species may be renamed for a few reasons:

  1. Botanists in different regions named the same plant without knowing it had already been classified.
  2. A species was reclassified after scientific advances in, for example, DNA analysis.
  3. Slight variations within a species are sometimes mistakenly identified as entirely new species.

Classification

Group: Dicot
Kingdom: Plantae - Plants
Subkingdom: Tracheobionta - Vascular plants
Superdivision: Spermatophyta - Seed plants
Division: Magnoliophyta - Flowering plants
Class: Magnoliopsida - Dicotyledons
Subclass: Asteridae
Order: Solanales
Family: Solanaceae Juss. - Potato family
Genus: Solanum L. - nightshade

Species: Solanum sandwicense Hook. & Arn. - Hawai'i horsenettle

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA