North America Native Plant

Cataract Scopelophila Moss

Botanical name: Scopelophila cataractae

USDA symbol: SCCA18

Habit: nonvascular

Native status: Native to North America  

Synonyms: Tortula williamsii E.B. Bartram (TOWI)   

Cataract Scopelophila Moss: A Rare Gem for Water-Loving Gardeners If you’ve ever wondered about those tiny green carpets clinging to rocks near waterfalls, you might have spotted the elusive cataract scopelophila moss. This North American native is one of nature’s more specialized residents, and while it’s not your typical garden ...

Rare plant alert!

Region: Conservation status by state

Status: S3: 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 ⚘

Cataract Scopelophila Moss: A Rare Gem for Water-Loving Gardeners

If you’ve ever wondered about those tiny green carpets clinging to rocks near waterfalls, you might have spotted the elusive cataract scopelophila moss. This North American native is one of nature’s more specialized residents, and while it’s not your typical garden center find, it’s worth getting to know this fascinating little plant.

What Exactly Is Cataract Scopelophila Moss?

Scopelophila cataractae (sometimes known by its former name Tortula williamsii) is a bryophyte – essentially a non-flowering plant that belongs to the moss family. Unlike your lawn grass or garden flowers, mosses are ancient plants that reproduce through spores rather than seeds and don’t have true roots, stems, or leaves in the traditional sense.

This particular moss is a terrestrial species that loves to attach itself to solid surfaces like rocks, dead wood, or other stable substrates rather than growing directly in soil. Think of it as nature’s living velvet, creating soft green patches wherever conditions are just right.

Where Does It Call Home?

As a North American native, cataract scopelophila moss has earned its cataract common name honestly – it’s typically found near waterfalls, seeps, and other consistently moist rocky areas. These specialized habitats provide the high humidity and steady moisture that this moss absolutely craves.

A Word of Caution: This Moss Is Rare

Here’s where things get serious for a moment. Cataract scopelophila moss has a Global Conservation Status of S3, meaning it’s considered vulnerable. With typically only 21 to 100 occurrences and between 3,000 to 10,000 individuals worldwide, this isn’t a plant to take lightly.

If you’re thinking about incorporating this moss into your landscape, please ensure you source it responsibly. Never harvest it from the wild, and only work with reputable suppliers who can guarantee their material comes from sustainable cultivation rather than wild collection.

Is It Beneficial in Your Garden?

While cataract scopelophila moss won’t attract butterflies or hummingbirds like flowering plants do, it can play some valuable roles in the right garden setting:

  • Provides natural ground cover for moisture-rich areas
  • Helps prevent soil erosion on slopes and around water features
  • Creates habitat for tiny invertebrates and microorganisms
  • Adds authentic naturalistic appeal to rock gardens and water features
  • Requires virtually no maintenance once established

Perfect Garden Scenarios

This moss isn’t for every garden, but it can be absolutely perfect in specific situations:

  • Rock gardens with consistent moisture
  • Areas around water features, fountains, or artificial waterfalls
  • Shaded spots with natural stone walls or boulders
  • Naturalized woodland gardens with year-round humidity
  • Specialized moss gardens for bryophyte enthusiasts

How to Identify Cataract Scopelophila Moss

Spotting this moss in the wild (though remember, don’t disturb it!) requires looking in the right places. You’ll typically find it forming thin patches or small cushions on wet rocks, especially limestone or other alkaline substrates near flowing water.

The moss appears as small, green tufts that can range from bright green when moist to slightly brownish when dry. Like most mosses, it’s quite small – individual plants rarely exceed a few centimeters in height.

Growing Conditions (For the Adventurous Gardener)

If you do decide to work with this special moss, here’s what it needs to thrive:

  • Moisture: Consistent humidity and regular water – think never quite dry
  • Light: Shade to partial shade; direct sunlight will quickly stress it
  • Substrate: Rocky surfaces, especially limestone or alkaline stone
  • Climate: Cool, humid conditions; likely hardy in USDA zones 3-8
  • Maintenance: Minimal once established, but requires consistent moisture

The Bottom Line

Cataract scopelophila moss is definitely not for every gardener or every garden. Its specific needs and rare status make it a plant for specialists and dedicated water gardeners rather than casual landscapers. However, if you have the right conditions and can source it responsibly, this little moss can add an authentic, naturalistic touch that few other plants can match.

For most gardeners, appreciating this moss in its natural habitat might be the best approach. But for those with the right setup and commitment to conservation, it represents a unique opportunity to cultivate one of nature’s more specialized and vulnerable treasures.

Cataract Scopelophila 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

Scopelophila (Mitt.) Lindb. - scopelophila moss

Species

Scopelophila cataractae (Mitt.) Broth. - cataract scopelophila moss

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