North America Native Plant

Dedulrarubak

Botanical name: Phyllanthus rupiinsularis

USDA symbol: PHRU9

Life cycle: perennial

Habit: shrub

Native status: Native to Pacific Basin excluding Hawaii  

Synonyms: Phyllanthus rupiinsularis Hosok., orth. var. (PHRU10)   

Dedulrarubak: A Rare Pacific Island Treasure Worth Knowing About If you’ve never heard of dedulrarubak (Phyllanthus rupiinsularis), you’re not alone! This little-known shrub is one of the Pacific’s best-kept secrets, quietly growing on just a couple of islands while most of the gardening world remains completely unaware of its existence. ...

Dedulrarubak: A Rare Pacific Island Treasure Worth Knowing About

If you’ve never heard of dedulrarubak (Phyllanthus rupiinsularis), you’re not alone! This little-known shrub is one of the Pacific’s best-kept secrets, quietly growing on just a couple of islands while most of the gardening world remains completely unaware of its existence.

What Exactly Is Dedulrarubak?

Dedulrarubak is a perennial shrub that typically grows as a multi-stemmed woody plant, usually staying under 13 to 16 feet tall. Like many members of the Phyllanthus family, it’s built to last, with several stems arising from or near the ground level. Think of it as nature’s way of creating a resilient, bushy presence in the landscape.

Where Does This Mystery Plant Call Home?

Here’s where things get really interesting – and a bit exclusive. Dedulrarubak is native to the Pacific Basin (excluding Hawaii) and currently grows wild in only two places on Earth: Guam and Palau. That’s it! This makes it one of those truly special endemic species that exists nowhere else naturally.

Should You Try Growing Dedulrarubak?

Here’s the honest truth: while dedulrarubak sounds fascinating, it presents some real challenges for the average gardener. The biggest hurdle? Finding it! Since this shrub has such a limited natural range, it’s extremely difficult to source seeds or plants through typical gardening channels.

If you do somehow manage to get your hands on this rare beauty, you’d be participating in something pretty special – the cultivation of a plant that most gardeners will never even see, let alone grow.

The Growing Reality Check

Unfortunately, detailed growing information for dedulrarubak is scarce. We know it’s adapted to Pacific island conditions, which suggests it likely prefers:

  • Warm, tropical to subtropical climates
  • Well-draining soils (as most island plants do)
  • Protection from harsh, drying winds
  • Consistent moisture without waterlogging

Without specific hardiness zone data, it’s safe to assume this plant would struggle in areas that experience freezing temperatures.

A Conservation Perspective

Rather than focusing solely on cultivation, perhaps the more important conversation around dedulrarubak involves conservation. With such a restricted range, this species represents the kind of botanical diversity that makes our planet’s flora so remarkable – and so vulnerable.

If you’re passionate about Pacific island plants, consider supporting conservation efforts in Guam and Palau, or look into growing other members of the Phyllanthus family that are more readily available and better understood horticulturally.

The Bottom Line

Dedulrarubak is undeniably cool – a rare shrub with a name that’s fun to say and a story that spans just two tiny dots in the vast Pacific Ocean. While it might not be practical for most gardeners to grow, knowing about plants like this reminds us of the incredible diversity that exists in our world’s flora.

If you’re drawn to unique, lesser-known plants, you might have better luck exploring other Phyllanthus species or focusing on native plants from your own region that need gardeners’ love and attention. Sometimes the most exotic garden addition is the native plant that’s been overlooked in your own backyard!

Dedulrarubak

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

Euphorbiales

Family

Euphorbiaceae Juss. - Spurge family

Genus

Phyllanthus L. - leafflower

Species

Phyllanthus rupi-insularis Hosok. - dedulrarubak

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