North America Native Plant

Physcomitrium Moss

Botanical name: Physcomitrium collenchymatum

USDA symbol: PHCO43

Habit: nonvascular

Native status: Native to North America  

Physcomitrium Moss: A Tiny Native Wonder in Your Garden Have you ever noticed tiny, carpet-like green patches growing on rocks, logs, or even concrete surfaces around your property? You might be looking at physcomitrium moss (Physcomitrium collenchymatum), a fascinating native North American bryophyte that’s been quietly doing its thing long ...

Rare plant alert!

Region: Conservation status by state

Status: S2S4: Status is uncertain but is somewhere between the following rankings: 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) ⚘ 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 ⚘

Physcomitrium Moss: A Tiny Native Wonder in Your Garden

Have you ever noticed tiny, carpet-like green patches growing on rocks, logs, or even concrete surfaces around your property? You might be looking at physcomitrium moss (Physcomitrium collenchymatum), a fascinating native North American bryophyte that’s been quietly doing its thing long before we started worrying about curb appeal.

What Exactly Is Physcomitrium Moss?

Physcomitrium moss belongs to that ancient group of plants called bryophytes – think of them as the great-grandparents of the plant world. Unlike their flashier flowering cousins, mosses like this one are small, herbaceous plants that have mastered the art of living simply. They don’t need soil to thrive; instead, they’re perfectly content attaching themselves to rocks, dead wood, or other solid surfaces.

This particular moss is native to North America, making it a true local resident that’s been part of our ecosystems for countless generations. However, it does carry a conservation status of S2S4, which suggests it may be somewhat uncommon in parts of its range, though the exact distribution details remain unclear.

Is This Moss Good for Your Garden?

Here’s where things get interesting – physcomitrium moss isn’t something you typically plant on purpose, but that doesn’t mean it’s unwelcome! If this little green pioneer decides to make itself at home in your garden, consider yourself lucky to be hosting a native species.

Benefits of having physcomitrium moss around:

  • Helps prevent soil erosion on slopes and bare spots
  • Adds natural texture and year-round green color
  • Requires absolutely zero maintenance once established
  • Provides habitat for tiny invertebrates
  • Indicates good air quality (mosses are sensitive to pollution)

How to Identify Physcomitrium Moss

Spotting this moss requires getting down to its level – literally. Look for small, green patches that form low-growing mats or cushions. You’ll most likely find it growing on:

  • Rock surfaces and stone walls
  • Dead or decaying wood
  • Concrete steps or foundations
  • Sometimes on compacted soil

The moss will appear as tiny, individual plants clustered together, creating that characteristic velvety appearance that makes you want to reach out and touch it (go ahead, it won’t mind!).

Should You Encourage It?

If physcomitrium moss shows up in your garden naturally, there’s really no reason to discourage it. This native species is doing its part in the local ecosystem, and it’s certainly not going to compete with your prized petunias for attention.

The best approach? Simply let it be. Mosses like this one are indicators of a healthy environment, and they add a subtle, natural beauty that many gardeners are starting to appreciate. Plus, with its potential conservation concerns, any naturally occurring populations deserve our respect and protection.

The Bottom Line

Physcomitrium moss might not make it onto your garden center wish list, but it’s one of those quiet garden residents that adds authenticity and ecological value to your outdoor spaces. If you’re lucky enough to have it growing naturally on your property, consider it a sign that your garden is providing habitat for North America’s native species – even the small, humble ones that often go unnoticed.

Sometimes the best gardening approach is simply appreciating what nature provides, and this little moss is a perfect example of that philosophy in action.

Physcomitrium Moss

Classification

Group

Moss

Kingdom

Plantae - Plants

Subkingdom
Superdivision
Division

Bryophyta - Mosses

Subdivision

Musci

Class

Bryopsida - True mosses

Subclass

Bryidae

Order

Funariales

Family

Funariaceae Schwägr.

Genus

Physcomitrium (Brid.) Brid. - physcomitrium moss

Species

Physcomitrium collenchymatum Gier - physcomitrium moss

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