North America Native Plant

Steere’s Sphagnum

Botanical name: Sphagnum steerei

USDA symbol: SPST70

Habit: nonvascular

Native status: Native to North America  

Synonyms: Sphagnum imbricatum Hornsch. ex Russow var. arcticum Flatberg (SPIMA3)   

Steere’s Sphagnum: The Arctic Moss That’s More Than Meets the Eye Meet Steere’s sphagnum (Sphagnum steerei), a fascinating little moss that might just change how you think about these often-overlooked garden inhabitants. While most gardeners focus on flashy flowers and towering trees, this unassuming moss plays a crucial role in ...

Steere’s Sphagnum: The Arctic Moss That’s More Than Meets the Eye

Meet Steere’s sphagnum (Sphagnum steerei), a fascinating little moss that might just change how you think about these often-overlooked garden inhabitants. While most gardeners focus on flashy flowers and towering trees, this unassuming moss plays a crucial role in some of North America’s most pristine ecosystems.

What Exactly Is Steere’s Sphagnum?

Steere’s sphagnum is a specialized moss native to North America, belonging to the remarkable sphagnum family. Unlike your typical lawn moss, this little green wonder is a terrestrial plant that prefers to attach itself to rocks, logs, or other solid surfaces rather than growing directly in soil. It’s herbaceous by nature and creates those distinctive spongy, cushion-like patches you might notice in boggy areas.

You might also see it referenced by its synonym, Sphagnum imbricatum var. arcticum, in older botanical texts, but Sphagnum steerei is the accepted name today.

Where Does It Call Home?

This hardy little moss has claimed some of the most challenging real estate in North America – the arctic and subarctic regions. You’ll find it thriving in Alaska, across northern Canada, and in high-elevation spots throughout the northern Rocky Mountains. It’s perfectly adapted to those harsh, cold climates that would make most plants throw in the towel.

Spotting Steere’s Sphagnum in the Wild

Identifying this moss is like learning to recognize a subtle but distinctive friend. Here’s what to look for:

  • Dense, cushion-like mats with a distinctly spongy texture
  • Pale green to yellowish-green coloration
  • Soft, almost pillow-like appearance when healthy
  • Typically found attached to rocks, fallen logs, or other solid surfaces
  • Prefers consistently moist, boggy conditions

Is It Beneficial to Have in Your Garden?

Here’s where things get interesting. While Steere’s sphagnum won’t directly attract butterflies or hummingbirds like flowering plants do, it offers some unique benefits that make it worth appreciating:

Moisture Management: Like other sphagnum mosses, it acts like a natural sponge, absorbing and slowly releasing moisture. This makes it incredibly valuable for water retention in naturalistic garden settings.

Habitat Creation: It provides crucial microhabitat for tiny creatures like springtails, mites, and other beneficial soil organisms that keep garden ecosystems healthy.

Soil Building: Over time, sphagnum mosses contribute to soil formation and help create the acidic conditions that many native plants love.

Can You Grow It in Your Garden?

Here’s the reality check: Steere’s sphagnum is extremely specialized and challenging to establish outside its natural arctic habitat. It requires very specific conditions that are difficult to replicate in most home gardens:

  • Consistently cold temperatures (thrives in USDA zones 1-6)
  • Constantly moist to wet, acidic conditions
  • Partial to full shade
  • Nutrient-poor, bog-like environment

Unless you live in its native range and have a specialized bog garden or natural wetland area, you’re probably better off appreciating this moss in its wild habitat rather than trying to cultivate it.

The Bottom Line

Steere’s sphagnum is one of those quiet heroes of the plant world – not flashy, but absolutely essential to the ecosystems where it thrives. While it’s not a practical choice for most home gardens, understanding and appreciating these specialized mosses helps us better understand the incredible diversity of plant life that surrounds us.

If you’re lucky enough to encounter it during hikes in arctic or subarctic regions, take a moment to appreciate this resilient little moss that’s perfectly adapted to some of the planet’s most challenging conditions. Sometimes the smallest plants have the biggest stories to tell.

Steere’s Sphagnum

Classification

Group

Moss

Kingdom

Plantae - Plants

Subkingdom
Superdivision
Division

Bryophyta - Mosses

Subdivision

Musci

Class

Sphagnopsida - Peat mosses

Subclass

Sphagnidae

Order

Sphagnales

Family

Sphagnaceae Dumort.

Genus

Sphagnum L. - sphagnum

Species

Sphagnum steerei R.E. Andrus - Steere's sphagnum

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