North America Native Plant

Coastal Sandmat

Botanical name: Chamaesyce skottsbergii var. vaccinioides

USDA symbol: CHSKV

Life cycle: perennial

Habit: subshrub

Native status: Native to Hawaii  

Synonyms: Chamaesyce multiformis (Gaudich. ex Hook. & Arn.) Croizat & O. Deg. var. haleakalana (Sherff) O. Deg. & I. Deg. (CHMUH)  âš˜  Chamaesyce multiformis (Gaudich. ex Hook. & Arn.) Croizat & O. Deg. var. kapuleiensis (O. Deg. & Sherff) O. Deg. & Sherff (CHMUK2)  âš˜  Euphorbia multiformis Gaudich. ex Hook. & Arn. var. haleakalana Sherff (EUMUH)  âš˜  Euphorbia multiformis Gaudich. ex Hook. & Arn. var. kapuleiensis O. Deg. & Sherff (EUMUK2)   

Coastal Sandmat: A Rare Hawaiian Native Worth Protecting Meet the coastal sandmat (Chamaesyce skottsbergii var. vaccinioides), a little-known Hawaiian treasure that’s as rare as it is resilient. This perennial shrub might not be sitting pretty at your local nursery, but it deserves a spot in our conversation about native Hawaiian ...

Rare plant alert!

Region: Conservation status by state

Status: S2T1: Status is uncertain but is somewhere between the following rankings: Subspecies or variety is 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) ⚘ Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 6 to 20 occurrences or few remaining individuals (1,000 to 3,000) ⚘

Coastal Sandmat: A Rare Hawaiian Native Worth Protecting

Meet the coastal sandmat (Chamaesyce skottsbergii var. vaccinioides), a little-known Hawaiian treasure that’s as rare as it is resilient. This perennial shrub might not be sitting pretty at your local nursery, but it deserves a spot in our conversation about native Hawaiian plants and conservation gardening.

What Makes Coastal Sandmat Special?

Coastal sandmat is a native Hawaiian shrub that belongs to the diverse Chamaesyce genus. As a perennial woody plant, it typically grows as a multi-stemmed shrub, usually staying under 13-16 feet in height. Like many Hawaiian natives, it has adapted to thrive in the unique island environment that shaped it over thousands of years.

Where Does It Call Home?

This plant is exclusively native to Hawaii, making it a true island endemic. You won’t find coastal sandmat growing naturally anywhere else in the world – it’s as uniquely Hawaiian as you can get!

The Conservation Reality Check

Here’s where things get serious: coastal sandmat has a Global Conservation Status of S2T1, indicating it’s extremely rare and potentially at risk. This isn’t a plant you’ll casually stumble upon, and that rarity makes it both precious and problematic for home gardeners.

If you’re considering adding this species to your garden, responsible sourcing is absolutely critical. This means:

  • Only purchasing from reputable native plant nurseries that propagate from legally collected seeds
  • Never collecting from wild populations
  • Supporting conservation efforts for Hawaiian native plants
  • Understanding that availability will be extremely limited

Growing Coastal Sandmat: What We Know

While specific growing information for this variety is limited, we can make some educated guesses based on its Hawaiian origins and shrub classification:

As a Hawaiian native, coastal sandmat likely prefers well-draining soils and can probably handle some drought once established. Most Hawaiian coastal plants have adapted to sandy, rocky soils and occasional salt spray, though the specific habitat preferences of this variety aren’t well documented.

The shrub growth habit suggests it could potentially work in landscape settings where you want a medium-sized, multi-stemmed plant. However, given its rarity, this would only be appropriate with responsibly propagated specimens.

Should You Plant Coastal Sandmat?

The honest answer? Probably not, unless you’re involved in serious conservation work or have access to legitimately propagated plants through conservation programs. The extreme rarity of this species means it’s better left to botanical gardens, conservation organizations, and specialized native plant enthusiasts who can ensure proper care and propagation.

Instead, consider these more readily available Hawaiian natives that can give you that authentic island feel:

  • Other Chamaesyce species that are less rare
  • Native Hawaiian grasses and sedges
  • More common Hawaiian shrubs like naupaka or ‘a’ali’i

Supporting Hawaiian Plant Conservation

Even if you can’t grow coastal sandmat in your garden, you can still support Hawaiian native plant conservation by:

  • Choosing other native Hawaiian plants for your landscape
  • Supporting organizations working to protect rare Hawaiian species
  • Learning about and sharing information about Hawaiian plant conservation
  • Avoiding invasive species that threaten native habitats

Coastal sandmat might be too rare for most of our gardens, but it serves as a beautiful reminder of Hawaii’s unique botanical heritage and the importance of protecting these irreplaceable island treasures for future generations.

Coastal 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 skottsbergii (Sherff) Croizat & O. Deg. - coastal sandmat

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