Native Plants

Eared Starviolet

Exallage auricularia

USDA symbol: EXAU

perennial forb

Pacific Basin excluding Hawaii: native

If you’ve never heard of the eared starviolet, you’re definitely not alone! This little-known native plant represents one of the Pacific’s more mysterious botanical treasures. While Exallage auricularia might not be showing up at your local nursery anytime soon, it’s worth understanding what makes this Pacific island endemic so special. ...

Eared Starviolet: A Rare Pacific Island Native Worth Knowing

If you’ve never heard of the eared starviolet, you’re definitely not alone! This little-known native plant represents one of the Pacific’s more mysterious botanical treasures. While Exallage auricularia might not be showing up at your local nursery anytime soon, it’s worth understanding what makes this Pacific island endemic so special.

What is Eared Starviolet?

The eared starviolet is a perennial herbaceous plant that belongs to the coffee family (Rubiaceae). As a forb, it lacks the woody stems of shrubs and trees, instead growing as a soft-stemmed plant that returns year after year. The name starviolet hints at its likely star-shaped flowers, though detailed descriptions of its appearance are surprisingly scarce in botanical literature.

Where Does Eared Starviolet Grow?

This native plant calls the Pacific Basin home, specifically found in Guam and Palau. These tropical island locations suggest the plant has evolved to thrive in warm, humid conditions typical of Pacific island ecosystems. Its limited range makes it a true endemic species – one that exists nowhere else on Earth.

  • Species observed
  • No observations

Why Should Gardeners Care About This Plant?

Here’s where things get interesting – and a bit challenging. The eared starviolet represents the fascinating world of island endemics, but it’s also a perfect example of why native plant gardening can be complicated. Here are the key considerations:

The Conservation Angle

  • As a Pacific island endemic, this species likely faces habitat pressures
  • Island plants often have highly specialized growing requirements
  • Many Pacific island natives are becoming increasingly rare

The Practical Reality

  • Seeds or plants are virtually impossible to obtain commercially
  • Specific growing requirements remain largely undocumented
  • Climate requirements likely limit growing success to tropical zones

Growing Eared Starviolet: What We Know (And Don’t Know)

Unfortunately, detailed cultivation information for Exallage auricularia is extremely limited. What we can infer from its native habitat suggests it would need:

  • Tropical or subtropical conditions similar to Guam and Palau
  • High humidity and consistent warmth
  • Well-draining soil typical of Pacific island environments
  • Protection from cold temperatures

The reality is that most gardeners won’t have the opportunity to grow this specific species, and that’s probably okay from a conservation standpoint.

Alternatives for Pacific Plant Enthusiasts

If you’re drawn to Pacific island plants but live outside the tropics, consider these more widely available options:

  • Hawaiian native plants suited to your climate zone
  • Other Rubiaceae family members that are better documented
  • Native plants from your own region that support local ecosystems

The Bigger Picture

The eared starviolet reminds us that the plant kingdom still holds many mysteries, especially on remote Pacific islands. While we may not be able to grow this particular species in our gardens, we can appreciate its role in Pacific island biodiversity and support conservation efforts that protect these unique ecosystems.

Sometimes the most important native plants are the ones we admire from afar while focusing our gardening efforts on the native species we can actually grow successfully in our own regions. After all, every native plant – whether it’s a common backyard wildflower or a rare Pacific island endemic – plays a vital role in supporting the web of life.

Exallage auricularia 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. Exallage auricularia is also known as:

Hedyotis auricularia | USDA symbol: HEAU4
Hedyotis auricularia var. dispersa Fosberg & | USDA symbol: HEAUD
Oldenlandia auricularia | USDA symbol: OLAU
Oldenlandia auricularia ssp. auricularia | USDA symbol: OLAUA

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: Rubiales
Family: Rubiaceae Juss. - Madder family
Genus: Exallage Bremek.

Species: Exallage auricularia (L.) Bremek. - eared starviolet

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