Non-native Plants

Aboriginal Willowherb

Epilobium billardierianum

USDA symbol: EPBI2

perennial forb

Hawaii: non-native, naturalized

If you’ve stumbled across the name aboriginal willowherb in your gardening research, you might be wondering what exactly this plant is and whether it belongs in your Hawaiian garden. Let’s dive into what we know about this somewhat mysterious member of the willowherb family. Aboriginal willowherb (Epilobium billardierianum) is a ...

Aboriginal Willowherb: A Little-Known Perennial for Hawaiian Gardens

If you’ve stumbled across the name aboriginal willowherb in your gardening research, you might be wondering what exactly this plant is and whether it belongs in your Hawaiian garden. Let’s dive into what we know about this somewhat mysterious member of the willowherb family.

What is Aboriginal Willowherb?

Aboriginal willowherb (Epilobium billardierianum) is a perennial forb that has made its way to Hawaii, though it’s not originally from the islands. As a forb, it’s essentially a soft-stemmed plant without the woody growth you’d see in shrubs or trees. Think of it as a herbaceous perennial that comes back year after year, but stays relatively low and non-woody.

Where You’ll Find It

Currently, this plant has established itself in Hawaii, where it reproduces on its own in the wild. It’s what botanists call naturalized – meaning it’s settled in and made itself at home without human help.

  • Species observed
  • No observations

Garden Characteristics

Based on its classification and what we know about related willowherbs, aboriginal willowherb likely produces small, delicate flowers typical of the Epilobium family. These plants are generally known for their:

  • Modest height and spreading growth habit
  • Small pink or purple flowers
  • Ability to attract small pollinators like bees and butterflies
  • Tolerance for varying moisture conditions

Growing Conditions and Care

One interesting aspect of aboriginal willowherb is its wetland status – it’s classified as facultative upland, which is a fancy way of saying it’s pretty flexible about moisture. You’ll usually find it in drier spots, but it can handle some wetness too. This adaptability could make it useful in gardens with varying moisture levels.

Should You Plant It?

Here’s where things get interesting. While aboriginal willowherb isn’t considered invasive or problematic, it’s also not native to Hawaii. For gardeners passionate about supporting local ecosystems, you might want to consider native Hawaiian alternatives first.

If you’re drawn to the idea of a low-growing perennial that can handle various moisture conditions, consider exploring native Hawaiian plants that might fill a similar niche in your garden design.

The Bottom Line

Aboriginal willowherb represents one of those in-between plants – not problematic enough to avoid entirely, but not native enough to be a first choice for ecosystem-conscious gardeners. If you do encounter it in the wild or choose to grow it, you’ll likely find it to be an undemanding perennial that quietly does its thing without much fuss.

As with any gardening decision, consider your specific goals, site conditions, and whether native alternatives might better serve both your garden and Hawaii’s unique ecosystem.

Wetland Status

The rule of seasoned gardeners and landscapers is to choose the "right plant for the right place" — matching plants to their ideal growing conditions, so they'll thrive with less care and fewer inputs. But the simplicity of this catchphrase conceals how tricky plant selection can be if you don't have the right information. While tags on nursery plants list watering requirements, there's more to the story.

Knowing a plant's wetland status can simplify the process by revealing the interaction between plants, water, and soil. You might be surprised to learn that popular landscape plants are wetland species! And what may be a wetland plant in one area, in another it might thrive in drier conditions. The table below gives insight into the preferred growing conditions of this plant throughout its geographical distribution.

Region
Preferred Habitat

Hawaii ()

Facultative Upland
Wetland Glossary
Obligate Wetland
Facultative Wetland
Facultative
Facultative Upland
Obligate Upland
Almost always occurs in wetlands
Usually occurs in wetlands but may occur in non-wetlands
Can occur in wetlands and non-wetlands
Usually occurs in non-wetlands but may occur in wetlands
Almost never occurs in wetlands

Classification

Group: Dicot
Kingdom: Plantae - Plants
Subkingdom: Tracheobionta - Vascular plants
Superdivision: Spermatophyta - Seed plants
Division: Magnoliophyta - Flowering plants
Subdivision: N/A
Class: Magnoliopsida - Dicotyledons
Subclass: Rosidae
Order: Myrtales
Family: Onagraceae Juss. - Evening Primrose family
Genus: Epilobium L. - willowherb

Species: Epilobium billardierianum Ser. - aboriginal willowherb

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