North America Non-native Plant

Island Glorybush

Botanical name: Trembleya phlogiformis var. parvifolia

USDA symbol: TRPHP

Life cycle: perennial

Habit: subshrub

Native status: Non-native, reproduces and persists in the wild in Hawaii  

Island Glorybush: A Lesser-Known Shrub in Hawaiian Landscapes If you’ve been exploring unique shrubs for warm-climate gardens, you might have stumbled across the island glorybush (Trembleya phlogiformis var. parvifolia). This perennial shrub has found its way into Hawaiian landscapes, though it remains something of a botanical mystery with limited cultivation ...

Island Glorybush: A Lesser-Known Shrub in Hawaiian Landscapes

If you’ve been exploring unique shrubs for warm-climate gardens, you might have stumbled across the island glorybush (Trembleya phlogiformis var. parvifolia). This perennial shrub has found its way into Hawaiian landscapes, though it remains something of a botanical mystery with limited cultivation information available.

What is Island Glorybush?

Island glorybush is a multi-stemmed woody shrub that typically grows less than 13-16 feet tall, though it can vary depending on environmental conditions. As a member of the Melastomataceae family, it shares characteristics with other tropical flowering shrubs known for their often showy blooms.

This perennial shrub develops several stems that arise from or near the ground, creating a bushy appearance that can add structure to tropical and subtropical gardens.

Native Status and Distribution

Here’s where things get interesting (and a bit concerning for native plant enthusiasts): island glorybush is not actually native to Hawaii, despite its common name. This non-native species has been introduced to the islands and now reproduces spontaneously in the wild without human intervention, showing its ability to persist in Hawaiian ecosystems.

Currently, you’ll find this plant growing in Hawaii, where it has established itself in the local flora.

Should You Plant Island Glorybush?

This is where gardeners need to think carefully. While island glorybush isn’t currently listed as invasive or noxious, its ability to reproduce and persist without human help in Hawaiian ecosystems raises some flags. Before adding this shrub to your landscape, consider these points:

  • Limited information exists about its long-term environmental impact
  • Its naturalization in Hawaii suggests it’s quite adaptable
  • Native Hawaiian plants might better serve local ecosystems

Growing Conditions and Care

Unfortunately, specific growing information for island glorybush is quite limited. Based on its success in Hawaii and its family characteristics, it likely prefers:

  • Warm, tropical to subtropical climates (probably USDA zones 10-11)
  • Well-draining soil
  • Regular moisture
  • Partial to full sun exposure

Without detailed cultivation guides available, growing this shrub would involve some experimentation and observation.

Consider Native Alternatives

Given the limited information about island glorybush and its non-native status, you might want to explore native Hawaiian shrubs instead. Native plants typically:

  • Support local wildlife and pollinators better
  • Are adapted to local growing conditions
  • Help preserve Hawaii’s unique ecological heritage
  • Often require less maintenance once established

The Bottom Line

Island glorybush remains something of an enigma in the gardening world. While it’s not flagged as invasive, its ability to naturalize in Hawaii and the lack of detailed cultivation information make it a questionable choice for most gardeners. If you’re drawn to flowering shrubs for your warm-climate garden, consider researching native alternatives that can provide beauty while supporting local ecosystems.

Remember, the best gardens work with nature rather than against it, and choosing plants that belong in your local ecosystem is usually the most rewarding path forward.

Island Glorybush

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Rosidae

Order

Myrtales

Family

Melastomataceae Juss. - Melastome family

Genus

Trembleya DC. - trembleya

Species

Trembleya phlogiformis DC. - island glorybush

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