Britannica AI Icon
Adding us as a Preferred Source tells Google you trust our content, so our articles show up more often in your Google Search, Discover feed, and AI Overviews.
verifiedCite
While every effort has been made to follow citation style rules, there may be some discrepancies. Please refer to the appropriate style manual or other sources if you have any questions.
Select Citation Style
Feedback
Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login).
Thank you for your feedback

Our editors will review what you’ve submitted and determine whether to revise the article.

Riccia, genus of liverworts (small, creeping plants) in the order Marchantiales, widely distributed throughout the world. The most well-known species, Riccia fluitans, sometimes called slender riccia, forms branching green ribbons about 0.1 centimetre (about 0.04 inch) wide and about 1.3 to 5 centimetres long that float in shallow ponds. The ribbons often become tangled in large masses. Other species of Riccia form rosettes on moist soils.