North America Native Plant

Aongstroem’s Sphagnum

Botanical name: Sphagnum aongstroemii

USDA symbol: SPAO70

Habit: nonvascular

Native status: Native to North America  

Aongstroem’s Sphagnum: A Rare Native Moss Worth Knowing If you’ve ever wandered through a boggy area or cool, moist woodland and noticed carpets of soft, spongy moss, you might have encountered one of nature’s most fascinating plant groups. Today, we’re diving into the world of Aongstroem’s sphagnum (Sphagnum aongstroemii), a ...

Rare plant alert!

Region: Conservation status by state

Status: S3S4: 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 ⚘ Apparently Secure: Uncommon but not rare, and usually widespread. Possibly cause for longterm concern. Typically more than 100 occurrences in the state or more than 10,000 individuals ⚘

Aongstroem’s Sphagnum: A Rare Native Moss Worth Knowing

If you’ve ever wandered through a boggy area or cool, moist woodland and noticed carpets of soft, spongy moss, you might have encountered one of nature’s most fascinating plant groups. Today, we’re diving into the world of Aongstroem’s sphagnum (Sphagnum aongstroemii), a native North American moss that’s both ecologically important and surprisingly garden-worthy.

What Exactly Is Aongstroem’s Sphagnum?

Aongstroem’s sphagnum belongs to the bryophyte family – that’s the technical term for mosses, liverworts, and hornworts. Unlike the flowering plants we’re used to, this little green wonder doesn’t have roots, stems, or leaves in the traditional sense. Instead, it’s a collection of tiny, simple structures that work together to create those lovely, cushiony moss carpets we love to see in nature.

What makes sphagnum mosses special is their incredible ability to hold water – up to 20 times their dry weight! Think of them as nature’s sponges, helping to regulate moisture in their environments.

Where You’ll Find This Native Beauty

As a native North American species, Aongstroem’s sphagnum has been quietly doing its job in our ecosystems for thousands of years. You’ll typically find it in the cooler regions of the continent, particularly in boreal and subarctic areas where conditions stay consistently cool and moist.

A Word About Rarity

Here’s something important to know: Aongstroem’s sphagnum has a conservation status of S3S4, which means it’s considered somewhat rare or uncommon in parts of its range. This doesn’t mean it’s endangered, but it does mean we should treat it with extra respect and care.

If you’re interested in encouraging this moss in your garden, please make sure any material comes from responsible sources – never harvest from wild populations!

Is Aongstroem’s Sphagnum Beneficial for Gardens?

Absolutely! While you won’t be planting this moss like you would a perennial, understanding and appreciating it can benefit your garden in several ways:

  • Natural soil conditioning: Sphagnum mosses help create acidic conditions that many native plants love
  • Moisture management: Their water-holding capacity helps maintain consistent soil moisture
  • Ecosystem support: They provide habitat for tiny creatures that form the base of healthy garden food webs
  • Natural beauty: Their soft, cushiony appearance adds texture and year-round interest to shady, moist areas

How to Identify Aongstroem’s Sphagnum

Identifying specific sphagnum species can be tricky even for experts, but here are some general characteristics to look for:

  • Color: Typically pale green, sometimes with reddish or brownish tints
  • Texture: Soft, spongy, and springy to the touch
  • Growth pattern: Forms cushions or carpets, often growing on rocks, decaying wood, or other solid surfaces rather than directly in soil
  • Habitat: Look for it in cool, consistently moist areas with partial to full shade

Creating Moss-Friendly Conditions

While you can’t exactly plant Aongstroem’s sphagnum like a traditional garden plant, you can create conditions that encourage native mosses to establish naturally:

  • Maintain consistent moisture: Mosses hate drying out completely
  • Provide shade: Most sphagnum species prefer partial to full shade
  • Keep it cool: These northern natives prefer cooler temperatures
  • Minimize disturbance: Mosses are slow-growing and don’t recover quickly from damage
  • Create acidic conditions: Most sphagnum species thrive in slightly acidic environments

The Bottom Line

Aongstroem’s sphagnum might not be the showiest addition to your garden, but it represents something valuable: the quiet, essential work that native species do to maintain healthy ecosystems. By learning to recognize and appreciate these small but mighty plants, we become better gardeners and better stewards of our local environments.

Whether you encounter this moss on a woodland walk or notice it establishing itself in a shady, moist corner of your garden, take a moment to appreciate this remarkable little survivor. Just remember – look but don’t disturb, especially given its somewhat rare status. Nature’s smallest players often have the biggest jobs to do!

Aongstroem’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 aongstroemii Hartm. - Aongstroem'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