North America Native Plant

Astomum Moss

Botanical name: Astomum ludovicianum

USDA symbol: ASLU5

Habit: nonvascular

Native status: Native to North America  

Synonyms: Hymenostomum rostellatum auct. Amer. (HYRO7)  ⚘  Weissia ludoviciana (Sull.) Reese & B.A.E. Lemmon (WELU)   

Astomum Moss: A Tiny Native Wonder for Your Garden Have you ever noticed those tiny, almost microscopic green patches growing in the shadier corners of your yard? You might be looking at astomum moss (Astomum ludovicianum), one of North America’s more diminutive native plants. While it may not steal the ...

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 ⚘

Astomum Moss: A Tiny Native Wonder for Your Garden

Have you ever noticed those tiny, almost microscopic green patches growing in the shadier corners of your yard? You might be looking at astomum moss (Astomum ludovicianum), one of North America’s more diminutive native plants. While it may not steal the spotlight like a showy wildflower, this little moss has its own quiet charm and ecological value.

What Exactly Is Astomum Moss?

Astomum moss is a bryophyte – that’s the fancy scientific term for the group that includes mosses, liverworts, and hornworts. Think of bryophytes as nature’s original ground cover, existing long before flowering plants showed up to the party. This particular species is a terrestrial moss, meaning it grows on land rather than in water, and you’ll often find it clinging to rocks, dead wood, or sometimes directly on soil.

You might also see this moss listed under some alternative scientific names in older references, including Hymenostomum rostellatum or Weissia ludoviciana, but Astomum ludovicianum is the currently accepted name.

Where Does Astomum Moss Call Home?

This moss is a true North American native, with its stronghold in the southeastern United States. While specific distribution details can be hard to pin down (mosses aren’t exactly the most studied plants!), it’s typically found in states like Louisiana, Texas, and Arkansas, along with neighboring regions.

Spotting Astomum Moss in the Wild

Identifying astomum moss requires a bit of detective work – and possibly a magnifying glass! Here’s what to look for:

  • Tiny yellowish-green shoots that form small cushions or patches
  • Growth on rocks, fallen logs, or sometimes bare soil
  • Prefers shaded, moist environments
  • Often grows alongside other small mosses and bryophytes

Honestly, unless you’re a bryophyte enthusiast, you might walk right past this moss without giving it a second glance. Its beauty lies in its understated presence rather than flashy displays.

Is Astomum Moss Good for Your Garden?

While astomum moss won’t provide nectar for butterflies or berries for birds like flowering plants do, it does offer some subtle benefits:

  • Helps prevent soil erosion in shady areas
  • Provides microhabitat for tiny insects and soil creatures
  • Adds textural interest to naturalistic garden designs
  • Requires zero maintenance once established
  • Contributes to the overall ecosystem diversity of your yard

Think of astomum moss as nature’s quiet worker – it’s not demanding attention, but it’s steadily doing its job in the background.

Conservation Considerations

Astomum moss has a conservation status of S3S4, which suggests it may be somewhat uncommon in parts of its range. While it’s not critically endangered, this is a good reminder that even small, seemingly insignificant plants play important roles in their ecosystems. If you’re lucky enough to have this moss growing naturally on your property, consider it a sign of a healthy, diverse landscape.

Creating Moss-Friendly Spaces

Rather than trying to actively plant astomum moss (which can be quite challenging with bryophytes), your best bet is to create conditions where native mosses like this one might naturally establish:

  • Maintain shaded areas with consistent moisture
  • Leave some fallen logs or rocks as potential growing surfaces
  • Avoid over-cleaning areas where mosses might want to grow
  • Reduce foot traffic in potential moss habitat

The Bottom Line

Astomum moss might not be the star of your garden show, but it represents something valuable: the intricate web of small, native species that make up healthy ecosystems. Whether you notice it or not, this tiny moss is quietly contributing to the biodiversity of North American landscapes. And sometimes, the smallest players deserve a moment of appreciation too.

So next time you’re wandering through a shady corner of your yard, take a closer look at those little green patches. You might just be admiring one of nature’s most understated natives.

Astomum Moss

Classification

Group

Moss

Kingdom

Plantae - Plants

Subkingdom
Superdivision
Division

Bryophyta - Mosses

Subdivision

Musci

Class

Bryopsida - True mosses

Subclass

Bryidae

Order

Pottiales

Family

Pottiaceae Hampe

Genus

Astomum Hampe - astomum moss

Species

Astomum ludovicianum (Sull.) Sull. - astomum moss

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