North America Native Plant

Lavaslope False Lobelia

Botanical name: Trematolobelia singularis

USDA symbol: TRSI5

Life cycle: perennial

Habit: shrub

Native status: Native to Hawaii  

Lavaslope False Lobelia: A Rare Hawaiian Treasure Worth Protecting If you’re passionate about Hawaiian native plants and conservation, you may have heard whispers about the lavaslope false lobelia (Trematolobelia singularis). This remarkable perennial shrub is one of Hawaii’s most endangered botanical treasures, and there’s quite a story behind why it ...

Rare plant alert!

Region: United States

Status: S1: Status is uncertain but is somewhere between the following rankings: Critically Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 5 or fewer occurrences or very few remaining individuals (<1,000) ⚘ Endangered: In danger of extinction throughout all or a significant portion of its range. ⚘

Region: United States

Lavaslope False Lobelia: A Rare Hawaiian Treasure Worth Protecting

If you’re passionate about Hawaiian native plants and conservation, you may have heard whispers about the lavaslope false lobelia (Trematolobelia singularis). This remarkable perennial shrub is one of Hawaii’s most endangered botanical treasures, and there’s quite a story behind why it deserves our attention and protection.

What Makes This Plant Special

The lavaslope false lobelia isn’t your typical garden center find. This multi-stemmed woody perennial typically grows to about 13-16 feet in height, though it can vary depending on environmental conditions. What makes it truly special isn’t just its size, but its incredible rarity and the unique role it plays in Hawaii’s native ecosystem.

True to its name, this plant calls the volcanic slopes of Hawaii home, where it has adapted to thrive in some pretty challenging conditions. It’s what botanists call a facultative wetland plant, meaning it’s equally happy in wet or drier conditions – a pretty handy trait when you’re living on a volcanic island!

Where You’ll Find It (If You’re Lucky)

Trematolobelia singularis is endemic to Hawaii, meaning it exists nowhere else on Earth. This plant has made the Hawaiian Islands its one and only home, specifically favoring those dramatic lavaslope environments that give it its common name.

Why This Plant Needs Our Help

Here’s where things get serious. The lavaslope false lobelia has a Global Conservation Status of S1, which translates to Critically Imperiled. In plain English, this means there are typically only 5 or fewer known populations, with fewer than 1,000 individual plants remaining in the wild. It’s also listed as Endangered, making it one of Hawaii’s most at-risk native species.

This rarity status means that if you’re considering adding this plant to your garden, you need to be extremely thoughtful about sourcing. We’re talking about a species teetering on the edge of extinction.

Growing Lavaslope False Lobelia: Proceed with Caution and Care

If you’re determined to grow this endangered beauty, here’s what you need to know:

Growing Conditions

  • Climate: USDA hardiness zones 10-11 only – this is strictly a tropical plant
  • Soil: Well-draining volcanic or rocky soils preferred
  • Water: Adaptable to both wet and dry conditions, but good drainage is essential
  • Light: Partial shade to full sun

The Responsible Approach

Before you even think about planting lavaslope false lobelia, you absolutely must ensure any plant material comes from legitimate, responsibly managed sources. This means:

  • Working with authorized native plant nurseries
  • Ensuring plants are propagated, not wild-collected
  • Supporting conservation efforts rather than depleting wild populations
  • Considering joining or supporting botanical gardens and conservation programs

Is This Plant Right for Your Garden?

Honestly? For most gardeners, the answer is probably no – and that’s okay! The lavaslope false lobelia is best suited for:

  • Specialized native Hawaiian plant collections
  • Botanical gardens with conservation programs
  • Experienced native plant enthusiasts in appropriate climates
  • Educational or research settings

If you’re drawn to the idea of supporting Hawaiian native plants but aren’t in a position to responsibly grow this rare species, consider supporting conservation organizations working to protect it, or explore other Hawaiian natives that aren’t quite so precarious.

The Bigger Picture

The lavaslope false lobelia represents something bigger than just one plant – it’s a reminder of how fragile our native ecosystems can be. While we don’t know much about its specific wildlife benefits, we do know that native plants like this one play crucial roles in supporting native pollinators and maintaining the ecological balance that makes Hawaii’s natural environments so special.

Sometimes the best way to grow a plant is to support its conservation in the wild. Whether that’s through donations, volunteer work, or simply spreading awareness, every bit helps ensure that future generations might have the chance to see lavaslope false lobelia thriving on Hawaiian mountainsides where it belongs.

Lavaslope False Lobelia

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Asteridae

Order

Campanulales

Family

Campanulaceae Juss. - Bellflower family

Genus

Trematolobelia Zahlbr. ex Rock - false lobelia

Species

Trematolobelia singularis H. St. John - lavaslope false lobelia

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