North America Native Plant

Lawton’s Racomitrium Moss

Botanical name: Racomitrium lawtonae

USDA symbol: RALA8

Habit: nonvascular

Native status: Native to North America  

Lawton’s Racomitrium Moss: A Tiny Mountain Marvel Worth Knowing Have you ever noticed those silvery-green patches clinging to rocks during mountain hikes? You might have been looking at Lawton’s racomitrium moss (Racomitrium lawtonae), one of North America’s more distinctive bryophytes. While you won’t be planting this little gem in your ...

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 ⚘

Lawton’s Racomitrium Moss: A Tiny Mountain Marvel Worth Knowing

Have you ever noticed those silvery-green patches clinging to rocks during mountain hikes? You might have been looking at Lawton’s racomitrium moss (Racomitrium lawtonae), one of North America’s more distinctive bryophytes. While you won’t be planting this little gem in your backyard anytime soon, understanding this fascinating moss can deepen your appreciation for the intricate world of native plants.

What Exactly Is Lawton’s Racomitrium Moss?

Racomitrium lawtonae belongs to the bryophyte family – that’s the technical term for mosses, liverworts, and hornworts. Unlike the flowering plants we’re used to, mosses are ancient, non-vascular plants that have been quietly doing their thing for millions of years. This particular species is a terrestrial moss, meaning it grows on land rather than in water, and it has a particular fondness for attaching itself to rocks and other solid surfaces.

What makes this moss special is its distinctive appearance. It forms small, cushion-like mats that range from grayish-green to dark green, with characteristic whitish hair points on the tips of its leaves that give it a somewhat hoary or frosted appearance.

Where Does This Moss Call Home?

As a native North American species, Lawton’s racomitrium moss has carved out its niche primarily in the mountainous regions of western North America. You’re most likely to encounter it in rocky, well-draining environments where it can anchor itself to stone surfaces and weather the elements.

Is This Moss Beneficial to Have Around?

While Racomitrium lawtonae won’t directly attract pollinators like flowering plants do, it plays several important ecological roles:

  • Prevents soil erosion by stabilizing rocky surfaces
  • Provides microhabitat for tiny invertebrates and insects
  • Contributes to nutrient cycling in mountain ecosystems
  • Adds textural interest and natural beauty to rocky landscapes

However, it’s worth noting that this species has a conservation status of S3S4, indicating it may be somewhat uncommon or vulnerable in parts of its range. This makes it more of a species to appreciate and protect rather than cultivate.

How to Identify Lawton’s Racomitrium Moss

Spotting this moss in the wild requires looking for these key characteristics:

  • Forms small, dense cushions or mats on rocky surfaces
  • Grayish-green to dark green coloration
  • Distinctive whitish hair points on leaf tips that give it a frosted appearance
  • Typically found in mountainous, well-draining rocky environments
  • Grows directly on rock surfaces rather than in soil

A Word About Cultivation

Here’s where things get interesting – or perhaps disappointing if you were hoping to add this to your garden. Mosses like Racomitrium lawtonae are notoriously difficult to cultivate outside their natural habitats. They have very specific requirements for moisture, light, and substrate that are challenging to replicate in typical garden settings.

Rather than attempting to grow this moss, consider creating habitat for more garden-friendly native mosses, or better yet, plan a hiking trip to observe Lawton’s racomitrium moss in its natural mountain home. Sometimes the best way to appreciate a plant is to visit it on its own terms.

The Bigger Picture

While you might not be adding Lawton’s racomitrium moss to your shopping list anytime soon, understanding species like this one helps us appreciate the incredible diversity of plant life that surrounds us. Every ecosystem, from your backyard to remote mountain peaks, is filled with fascinating organisms playing their own unique roles.

Next time you’re out exploring rocky terrain in western North America, take a moment to look closely at those seemingly simple moss patches. You might just be observing Racomitrium lawtonae, a small but important piece of our continent’s natural heritage.

Lawton’s Racomitrium Moss

Classification

Group

Moss

Kingdom

Plantae - Plants

Subkingdom
Superdivision
Division

Bryophyta - Mosses

Subdivision

Musci

Class

Bryopsida - True mosses

Subclass

Bryidae

Order

Grimmiales

Family

Grimmiaceae Arn.

Genus

Racomitrium Brid. - racomitrium moss

Species

Racomitrium lawtonae Irel. - Lawton's racomitrium moss

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