North America Native Plant

Wahiawa Bog Sandmat

Botanical name: Chamaesyce sparsiflora

USDA symbol: CHSP4

Life cycle: perennial

Habit: subshrub

Native status: Native to Hawaii  

Synonyms: Chamaesyce multiformis (Gaudich. ex Hook. & Arn.) Croizat & O. Deg. var. sparsiflora (A. Heller) O. Deg. & I. Deg. (CHMUS)  âš˜  Euphorbia multiformis Gaudich. ex Hook. & Arn. var. sparsiflora (A. Heller) Sherff (EUMUS)  âš˜  Euphorbia sparsiflora A. Heller (EUSP2)   

Wahiawa Bog Sandmat: A Critically Rare Hawaiian Treasure If you’re passionate about Hawaiian native plants and conservation, you may have heard whispers about the wahiawa bog sandmat (Chamaesyce sparsiflora). This tiny, unassuming shrub holds the distinction of being one of Hawaii’s most critically endangered plants—and that’s exactly why it deserves ...

Rare plant alert!

Region: Conservation status by state

Status: S1: Status is uncertain but is somewhere between the following rankings: Critically Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 5 or fewer occurrences or very few remaining individuals (<1,000) ⚘

Wahiawa Bog Sandmat: A Critically Rare Hawaiian Treasure

If you’re passionate about Hawaiian native plants and conservation, you may have heard whispers about the wahiawa bog sandmat (Chamaesyce sparsiflora). This tiny, unassuming shrub holds the distinction of being one of Hawaii’s most critically endangered plants—and that’s exactly why it deserves our attention and respect.

What Makes This Plant Special?

The wahiawa bog sandmat is a perennial shrub that’s found nowhere else on Earth except in Hawaii’s unique bog ecosystems. As a member of the spurge family, it’s related to more familiar plants like poinsettias, but don’t expect flashy red bracts. This modest plant keeps things simple with small leaves and inconspicuous flowers that blend seamlessly into its boggy home.

What truly sets this plant apart isn’t its appearance—it’s its rarity. With a Global Conservation Status of S1 (Critically Imperiled), there are typically only five or fewer known populations with less than 1,000 individuals remaining in the wild. That makes every single plant incredibly precious.

Where Does It Call Home?

This endemic Hawaiian species grows exclusively in the Hawaiian Islands, where it has adapted to life in specialized bog habitats. These wetland environments provide the unique conditions that wahiawa bog sandmat needs to survive.

Should You Grow Wahiawa Bog Sandmat?

Here’s where we need to have an honest conversation. While supporting native Hawaiian plants is absolutely wonderful, growing wahiawa bog sandmat comes with serious responsibilities and challenges:

  • Rarity concerns: With so few plants left in the wild, any cultivation should only be attempted with responsibly sourced material from legitimate conservation programs
  • Specialized needs: This plant requires facultative wetland conditions—it usually grows in wetlands but may occasionally be found in non-wetland areas
  • Climate requirements: It’s adapted to Hawaii’s tropical climate and won’t survive in most mainland gardens
  • Conservation priority: Wild populations need protection more than home gardens need specimens

Growing Conditions and Care

If you’re working with a legitimate conservation organization or botanical garden in Hawaii, here’s what wahiawa bog sandmat needs:

  • Moisture: Consistent wetland or bog-like conditions with high soil moisture
  • Climate: Tropical Hawaiian climate (USDA zones 10-12)
  • Soil: Specialized bog soils with appropriate drainage and organic content
  • Habitat: Native Hawaiian bog ecosystem conditions

Wildlife and Ecological Benefits

As part of Hawaii’s native ecosystem, wahiawa bog sandmat likely supports native Hawaiian insects and contributes to the complex web of bog habitat biodiversity. However, specific wildlife benefits are still being studied by researchers.

A Plant Worth Protecting

Rather than trying to grow wahiawa bog sandmat in your garden, consider supporting its conservation in other ways. You can contribute to Hawaiian native plant organizations, visit botanical gardens that participate in conservation efforts, or choose other native Hawaiian plants that are less critically endangered for your landscape.

Sometimes the best way to appreciate a rare plant is to ensure it continues to exist in its natural habitat for future generations to discover and protect. The wahiawa bog sandmat reminds us that not every native plant is meant for cultivation—some are meant to inspire us to be better stewards of the wild places they call home.

Wahiawa Bog Sandmat

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

Chamaesyce Gray - sandmat

Species

Chamaesyce sparsiflora (A. Heller) Koutnik - wahiawa bog sandmat

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