North America Native Plant

Riccia Curtisii

Botanical name: Riccia curtisii

USDA symbol: RICU2

Habit: nonvascular

Native status: Native to North America  

Riccia curtisii: The Tiny Liverwort You Might Already Have in Your Garden If you’ve ever noticed small, flat green patches growing on moist soil or rocks in your garden, you might have encountered a fascinating group of plants called liverworts. One such species native to North America is Riccia curtisii, ...

Riccia curtisii: The Tiny Liverwort You Might Already Have in Your Garden

If you’ve ever noticed small, flat green patches growing on moist soil or rocks in your garden, you might have encountered a fascinating group of plants called liverworts. One such species native to North America is Riccia curtisii, a diminutive but important member of our local ecosystem that’s worth getting to know.

What Exactly Is Riccia curtisii?

Riccia curtisii is a liverwort, which belongs to an ancient group of plants that includes mosses and hornworts. These aren’t your typical garden plants – they’re some of the oldest land plants on Earth! Unlike the flowering plants we’re used to seeing, liverworts are small, green, and grow as flat, leaf-like structures called thalli.

This particular species is herbaceous and terrestrial, meaning it grows on land rather than in water. You’ll often find it attached to solid surfaces like rocks, fallen logs, or even growing directly on soil. It’s completely native to North America, making it a legitimate member of our local plant communities.

Geographic Distribution

While we know Riccia curtisii calls North America home, the specific details of where you’re most likely to encounter it remain somewhat mysterious. Like many liverworts, it probably has a wider distribution than we realize – these small plants are often overlooked in botanical surveys.

Is This Liverwort Beneficial for Your Garden?

Here’s where things get interesting! While you probably won’t be rushing out to plant Riccia curtisii intentionally, having it show up naturally in your garden can actually be a good sign. Liverworts like this one indicate:

  • Healthy soil moisture levels
  • Good air quality (liverworts are sensitive to pollution)
  • A balanced ecosystem that supports diverse plant life
  • Natural soil stabilization on slopes or exposed areas

Since liverworts don’t produce flowers, they won’t directly attract pollinators like bees and butterflies. However, they do contribute to the overall biodiversity of your garden ecosystem and can provide microhabitats for tiny invertebrates.

How to Identify Riccia curtisii

Spotting this little liverwort takes a keen eye, as it’s quite small. Look for these characteristics:

  • Small, flat, green patches that look almost like tiny lettuce leaves
  • Grows close to the ground, typically less than an inch tall
  • Often found in moist, shaded areas
  • May appear on soil, rocks, or decaying wood
  • Has a somewhat glossy or smooth appearance when moist

Growing Conditions and Habitat

If Riccia curtisii appears in your garden naturally, it’s found the conditions it likes:

  • Moist but not waterlogged soil
  • Partial to full shade
  • Good air circulation
  • Stable surfaces to attach to

Rather than trying to cultivate this liverwort, your best bet is to maintain conditions that allow native species like this to thrive naturally. This means avoiding excessive use of chemicals, maintaining some moist, shaded areas in your landscape, and leaving some natural debris like fallen logs that can serve as growing surfaces.

The Bottom Line

Riccia curtisii isn’t a plant you’ll add to your shopping list, but it’s definitely one worth appreciating if it shows up in your garden. Consider it a tiny green ambassador from the ancient plant world – a living link to some of the first plants that made the leap from water to land millions of years ago. If you spot it growing naturally in your space, take a moment to marvel at this small but significant piece of North American botanical heritage!

Riccia Curtisii

Classification

Group

Liverwort

Kingdom

Plantae - Plants

Subkingdom
Superdivision
Division

Hepaticophyta - Liverworts

Subdivision

Hepaticae

Class

Hepaticopsida

Subclass

Marchantiae

Order

Marchantiales

Family

Ricciaceae Rchb.

Genus

Riccia L., nom. cons.

Species

Riccia curtisii (James ex Austin) Austin

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