North America Native Plant

Hapeman’s Coolwort

Botanical name: Sullivantia hapemanii var. hapemanii

USDA symbol: SUHAH

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Hapeman’s Coolwort: A Rare Rocky Mountain Gem for Specialized Gardens If you’re drawn to unique native plants that tell a story of resilience and adaptation, Hapeman’s coolwort (Sullivantia hapemanii var. hapemanii) might just capture your gardening heart. This delicate perennial forb is one of those special plants that makes rock ...

Rare plant alert!

Region: Conservation status by state

Status: S3T3: Status is uncertain but is somewhere between the following rankings: Vulnerable: Either very rare and local throughout its range, found only in a restricted range (even if abundant at some locations), or factors are making it vulnerable to extinction. Typically 21 to 100 occurrences or between 3,000 and 10,000 individuals ⚘ Subspecies or variety is vulnerable: Either very rare and local throughout its range, found only in a restricted range (even if abundant at some locations), or factors are making it vulnerable to extinction. Typically 21 to 100 occurrences or between 3,000 and 10,000 individuals. ⚘

Hapeman’s Coolwort: A Rare Rocky Mountain Gem for Specialized Gardens

If you’re drawn to unique native plants that tell a story of resilience and adaptation, Hapeman’s coolwort (Sullivantia hapemanii var. hapemanii) might just capture your gardening heart. This delicate perennial forb is one of those special plants that makes rock gardening enthusiasts do a little happy dance – though its rarity means you’ll need to be thoughtful about how you acquire it.

What Makes Hapeman’s Coolwort Special

Hapeman’s coolwort is a charming native perennial that forms neat little rosettes of rounded, scalloped leaves. During its blooming period, it sends up slender stems topped with clusters of tiny white flowers that seem to float like delicate stars above the foliage. This isn’t a plant that screams for attention – instead, it whispers its beauty to those who take the time to look closely.

As a true Rocky Mountain native, this coolwort has adapted to thrive in some pretty tough conditions, making it a testament to nature’s ingenuity in finding ways to flourish in challenging environments.

Where It Calls Home

Hapeman’s coolwort is native to the American West, specifically found growing wild in Idaho, Montana, and Wyoming. In nature, you’ll discover it tucked into rocky crevices and cliff faces, where it has mastered the art of living beautifully with very little soil and plenty of drainage.

Important Rarity Considerations

Here’s where we need to have a serious conversation: Hapeman’s coolwort has a Global Conservation Status of S3T3, which indicates it’s considered rare or uncommon throughout its range. This means that while it’s absolutely worth growing to support native biodiversity and preserve this unique species, you must be extremely careful about sourcing.

Only purchase from reputable nurseries that propagate their own stock – never collect from the wild or buy from sources that might have collected wild plants. By choosing responsibly propagated plants, you’re helping ensure this special species has a future both in gardens and in its native habitat.

Is Hapeman’s Coolwort Right for Your Garden?

This isn’t your typical garden center perennial, and that’s precisely what makes it so appealing to certain gardeners. Consider Hapeman’s coolwort if you:

  • Love rock gardens, alpine gardens, or crevice gardening
  • Enjoy growing unusual native plants
  • Have experience with plants that need excellent drainage
  • Want to support conservation through cultivation
  • Appreciate subtle beauty over flashy displays

However, this might not be the plant for you if you’re looking for bold color, easy care, or a plant that thrives in typical garden soil conditions.

Growing Conditions and Care

Think rocky mountain crevice and you’ll understand what Hapeman’s coolwort needs to thrive. This plant is all about drainage, drainage, drainage – it would much rather be too dry than too wet.

Soil requirements: Well-draining, rocky or gravelly soil is essential. Consider creating a specialized rock garden area or using containers filled with a very gritty mix.

Light needs: Partial shade to full sun, depending on your climate. In hotter areas, some afternoon shade will be appreciated.

Water needs: Once established, this is a drought-tolerant plant that prefers to stay on the dry side. Water deeply but infrequently.

Climate considerations: Hardy in USDA zones 3-6, this plant is built for cold winters and appreciates the temperature swings of mountain climates.

Planting and Care Tips

Success with Hapeman’s coolwort is all in the setup. Here’s how to give it the best start:

  • Create a well-draining planting area with lots of coarse sand, gravel, or small rocks mixed into the soil
  • Plant in spring after the last frost, giving plants adequate space for their mature size
  • Mulch with gravel or small stones rather than organic mulch
  • Avoid fertilizing – this plant is adapted to lean, nutrient-poor conditions
  • Be patient – like many alpine plants, it may take time to establish and show its best growth

Supporting Pollinators and Wildlife

While small, the delicate white flowers of Hapeman’s coolwort do provide nectar for tiny pollinators, including small bees and beneficial insects. Every native plant, no matter how modest, plays a role in supporting local ecosystems.

The Bottom Line

Hapeman’s coolwort is a plant for gardeners who appreciate the subtle and the special. If you’re drawn to rare natives and have the right growing conditions – or are willing to create them – this little Rocky Mountain gem can add something truly unique to your garden. Just remember to source it responsibly and treat it as the conservation treasure it is.

While it may not be the easiest plant to grow or find, there’s something deeply satisfying about successfully cultivating a piece of the American West’s botanical heritage right in your own backyard.

Hapeman’s Coolwort

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

Rosales

Family

Saxifragaceae Juss. - Saxifrage family

Genus

Sullivantia Torr. & A. Gray ex A. Gray - coolwort

Species

Sullivantia hapemanii (J.M. Coult. & Fisher) J.M. Coult. - Hapeman's coolwort

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