North America Native Plant

Riccia Californica

Botanical name: Riccia californica

USDA symbol: RICA12

Habit: nonvascular

Native status: Native to North America  

Riccia californica: A Rare California Liverwort Worth Knowing Meet Riccia californica, one of California’s lesser-known native treasures. This tiny liverwort might not grab attention like a showy wildflower, but it plays an important role in the Golden State’s diverse ecosystems. If you’ve ever wondered about those small, flat green patches ...

Rare plant alert!

Region: Conservation status by state

Status: S1S2: Status is uncertain but is somewhere between the following rankings: Critically Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 5 or fewer occurrences or very few remaining individuals (<1,000) ⚘ 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) ⚘

Riccia californica: A Rare California Liverwort Worth Knowing

Meet Riccia californica, one of California’s lesser-known native treasures. This tiny liverwort might not grab attention like a showy wildflower, but it plays an important role in the Golden State’s diverse ecosystems. If you’ve ever wondered about those small, flat green patches growing on rocks or fallen logs during your nature walks, you might have encountered this fascinating little plant.

What Exactly Is Riccia californica?

Riccia californica is a liverwort, which puts it in a completely different category from the flowering plants most gardeners know and love. Liverworts are among Earth’s oldest land plants, and they’re quite different from mosses, ferns, or typical garden plants. Think of them as nature’s green carpets – they form flat, branching structures called thalli that hug surfaces like rocks, fallen logs, or sometimes soil.

This particular species is native to North America, with its heart in California and the western regions. Unlike flowering plants, liverworts don’t produce seeds or flowers. Instead, they reproduce through spores, making them more similar to ferns in their reproductive strategy.

Where You’ll Find This California Native

Riccia californica calls western North America home, with California being its primary stomping ground. You’re most likely to spot it in naturally moist, shaded areas where it can attach itself to rocks, fallen wood, or occasionally soil surfaces.

A Plant Worth Protecting

Here’s something important to know: Riccia californica has a Global Conservation Status of S1S2, which means it’s considered rare to uncommon. This makes it a species of conservation concern, so if you’re lucky enough to encounter it in the wild, observe and appreciate it, but leave it undisturbed.

Identifying Riccia californica

Spotting this liverwort takes a keen eye since it’s quite small. Here’s what to look for:

  • Small, flat, green patches that branch in a distinctive Y-shaped (dichotomous) pattern
  • Typically found attached to rocks, fallen logs, or dead wood rather than growing in soil
  • Herbaceous texture that looks almost like tiny green ribbons
  • Prefers moist, shaded locations with good air circulation
  • Usually forms small colonies or patches rather than large expanses

Is It Beneficial for Your Garden?

While you shouldn’t try to cultivate Riccia californica due to its rarity status, understanding its role can help you appreciate the complexity of native ecosystems. Liverworts like this one serve as:

  • Indicators of healthy, undisturbed habitats
  • Contributors to soil formation and moisture retention in natural settings
  • Part of the intricate web of native biodiversity

If you’re interested in supporting native biodiversity in your garden, focus on creating habitat conditions that might naturally support rare species like this – areas with consistent moisture, good air circulation, and native rocks or fallen wood. However, always source any liverworts or bryophytes responsibly if you’re working with specialized native plant suppliers.

Supporting California’s Native Heritage

Rather than trying to grow this rare liverwort, consider it an inspiration for creating more naturalistic spaces in your landscape. By maintaining areas with native rocks, fallen wood, and consistent moisture, you’re creating the kind of microhabitats where rare species like Riccia californica can thrive naturally.

The next time you’re exploring California’s natural areas, keep an eye out for these tiny green gems. They’re a reminder that some of nature’s most important players are also its smallest and most easily overlooked.

Riccia Californica

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 californica Austin

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