Native Plants

Waianae Range Alsinidendron

Alsinidendron obovatum

USDA symbol: ALOB4

perennial subshrub

Hawaii: native

If you’re passionate about Hawaiian native plants and conservation, you’ve likely heard whispers about the Waianae Range alsinidendron (Alsinidendron obovatum). This isn’t your typical garden center find – it’s one of Hawaii’s most critically endangered shrubs, making it both fascinating and challenging for dedicated native plant enthusiasts. The Waianae Range ...

Waianae Range Alsinidendron may be listed as rare in your area.
Global Conservation Status

Status: S1 | Critically imperiled: Typically 5 or fewer occurrences or under 1,000 remaining individuals.

United States

Status: Endangered | Endangered. In danger of extinction throughout all or a significant portion of its range.

Waianae Range Alsinidendron: A Rare Hawaiian Treasure Worth Protecting

If you’re passionate about Hawaiian native plants and conservation, you’ve likely heard whispers about the Waianae Range alsinidendron (Alsinidendron obovatum). This isn’t your typical garden center find – it’s one of Hawaii’s most critically endangered shrubs, making it both fascinating and challenging for dedicated native plant enthusiasts.

What Makes This Plant Special?

The Waianae Range alsinidendron is a perennial shrub that typically grows as a multi-stemmed woody plant, usually staying under 13-16 feet tall. Like most shrubs, it develops several stems from near ground level, creating a naturally bushy appearance that’s perfectly suited to Hawaii’s unique landscape.

This remarkable plant belongs exclusively to Hawaii – it’s what botanists call an endemic species, meaning you won’t find it growing naturally anywhere else on Earth. Talk about island exclusivity!

Where Does It Call Home?

True to its common name, this rare beauty is found only in Hawaii, specifically in the Waianae Mountains of Oahu. Its distribution is incredibly limited, which is part of what makes it so special – and so vulnerable.

  • Species observed
  • No observations

A Plant in Crisis

Important Conservation Alert: Before we dive into growing tips, let’s talk about the elephant in the room. The Waianae Range alsinidendron has a Global Conservation Status of S1, which translates to Critically Imperiled. This means there are typically fewer than 1,000 individuals left in the wild, with only 5 or fewer known populations. It’s also officially listed as Endangered.

What does this mean for gardeners? If you’re considering adding this plant to your landscape, you absolutely must ensure any plant material comes from responsible, legal sources – preferably conservation programs or botanical institutions working to preserve the species.

Growing Conditions and Care

Let’s be honest – this isn’t a plant for beginners or casual gardeners. The Waianae Range alsinidendron has very specific needs that mirror its natural habitat:

  • Climate: Thrives in USDA hardiness zones 10-12 (essentially Hawaii’s year-round tropical climate)
  • Moisture: Prefers dry to moderately moist conditions – it’s classified as Facultative Upland, meaning it usually grows in non-wetland areas but can tolerate some moisture
  • Habitat: Native to rocky slopes and dry to mesic (moderately moist) forests

Is This Plant Right for Your Garden?

Here’s where we need to have a heart-to-heart. While the Waianae Range alsinidendron would be an incredible addition to any native Hawaiian landscape or specialized botanical collection, it’s not practical for most home gardeners. Here’s why:

  • Extreme rarity: Finding legitimate plant material is nearly impossible
  • Specialized care: Requires very specific growing conditions that are difficult to replicate
  • Conservation responsibility: Best left to professional conservation programs
  • Legal considerations: Harvesting from wild populations is illegal and harmful

Supporting Conservation Efforts

Instead of trying to grow this rare gem yourself, consider supporting conservation organizations working to preserve Hawaiian endemic plants. You can also explore other native Hawaiian shrubs that are more readily available and easier to grow, while still supporting local ecosystems.

If you’re determined to work with this species, connect with local botanical gardens, universities, or conservation groups. They may have legitimate propagation programs where you can contribute to conservation efforts rather than simply growing the plant for ornamental purposes.

The Bottom Line

The Waianae Range alsinidendron represents everything magical about Hawaii’s unique flora – and everything fragile about our island ecosystems. While it’s not a practical choice for most gardens, understanding and appreciating plants like this helps us become better stewards of our natural heritage.

Sometimes the best way to love a plant is to protect it in its natural habitat rather than bringing it into our gardens. In the case of Alsinidendron obovatum, that’s exactly the kind of love this critically endangered species needs most.

Alsinidendron obovatum 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. Alsinidendron obovatum is also known as:

Alsinidendron obovatum Sherff var. parvifolium & | USDA symbol: ALOBP
Schiedea obovata Wagner & | USDA symbol: SCOB6

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: Caryophyllidae
Order: Caryophyllales
Family: Caryophyllaceae Juss. - Pink family
Genus: Alsinidendron H. Mann - alsinidendron

Species: Alsinidendron obovatum Sherff - Waianae Range alsinidendron

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