North America Native Plant

Riella Americana

Botanical name: Riella americana

USDA symbol: RIAM6

Habit: nonvascular

Native status: Native to North America  

Riella americana: A Fascinating Native Liverwort You Might Spot in Seasonal Wetlands Have you ever stumbled across something green and leafy in a temporary puddle or seasonal wetland and wondered what on earth it was? You might have encountered Riella americana, one of North America’s more intriguing native liverworts. While ...

Rare plant alert!

Region: Conservation status by state

Status: S2?: Status is uncertain but is somewhere between the following rankings: Inexact rank: ⚘ 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) ⚘

Riella americana: A Fascinating Native Liverwort You Might Spot in Seasonal Wetlands

Have you ever stumbled across something green and leafy in a temporary puddle or seasonal wetland and wondered what on earth it was? You might have encountered Riella americana, one of North America’s more intriguing native liverworts. While this little plant won’t be gracing your garden beds anytime soon, it’s absolutely worth getting to know!

What Exactly Is Riella americana?

Riella americana belongs to that fascinating group of plants called liverworts – ancient, non-flowering plants that have been quietly doing their thing on Earth for hundreds of millions of years. Think of liverworts as the quirky cousins of mosses, but with their own unique personality and lifestyle.

This particular liverwort is a true North American native, making it part of our continent’s natural heritage. Unlike the plants you’re used to seeing in gardens, Riella americana doesn’t have traditional roots, stems, or leaves. Instead, it has ribbon-like or strap-shaped structures called thalli that do all the work of photosynthesis and water absorption.

Where You’ll Find This Elusive Plant

Riella americana has some pretty specific real estate requirements. You won’t find it growing in your typical garden soil or even in permanent ponds. This liverwort is a specialist of temporary pools and seasonal wetlands – those areas that flood during certain times of the year and then dry out completely.

It’s worth noting that Riella americana has a somewhat uncertain conservation status, which makes spotting one in the wild even more special. The rarity of suitable habitat makes this liverwort something of a treasure when you do encounter it.

How to Identify Riella americana

Spotting Riella americana requires being in the right place at the right time. Here’s what to look for:

  • Small, green, ribbon-like structures floating or attached to rocks and debris in seasonal pools
  • Typically appears during specific seasons when water levels are just right
  • Often grows attached to solid surfaces rather than rooted in soil
  • Much smaller and more delicate than typical aquatic plants

Is Riella americana Beneficial to Your Garden?

Here’s where we need to set realistic expectations: Riella americana isn’t a plant you can intentionally cultivate in your garden. Its specialized habitat requirements – including specific flooding and drying cycles, particular soil chemistry, and seasonal timing – make it nearly impossible to replicate in typical garden settings.

However, if you’re fortunate enough to have seasonal wetlands or temporary pools on your property, you might naturally support this species by:

  • Avoiding disturbance to seasonal wetland areas
  • Maintaining natural water flow patterns
  • Keeping these areas free from pollutants and excess nutrients

The Bigger Picture

While you can’t plant Riella americana in your perennial border, understanding and appreciating these specialized native species helps us become better stewards of our local ecosystems. Liverworts like Riella americana play important roles in their specific habitats, contributing to the complex web of life that makes up healthy wetland ecosystems.

If you’re interested in supporting native biodiversity in your own garden, consider focusing on native flowering plants, grasses, and shrubs that are more suited to cultivation. These will provide habitat and resources for the wildlife that depends on native plant communities – and you’ll have much better luck growing them!

So next time you’re exploring a seasonal wetland or temporary pool, keep an eye out for this fascinating little liverwort. You might just spot one of North America’s most specialized native plants doing what it does best – quietly thriving in its own unique corner of the natural world.

Riella Americana

Classification

Group

Liverwort

Kingdom

Plantae - Plants

Subkingdom
Superdivision
Division

Hepaticophyta - Liverworts

Subdivision

Hepaticae

Class

Hepaticopsida

Subclass

Marchantiae

Order

Sphaerocarpales

Family

Riellaceae Engl.

Genus

Riella Mont.

Species

Riella americana M. Howe & Underw.

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