
206522.jpg from: https://inpn.mnhn.fr/espece/cd_nom/6218?lg=en
Exploring the Fascinating World of Riccia glauca var. major (Roth) Bisch. Moss
Introduction
Mosses are often overlooked, but they play crucial roles in ecosystems around the world. One particularly interesting moss is Riccia glauca var. major (Roth) Bisch., also known simply as Riccia. This tiny but mighty plant is part of the

ricciaglauca.jpg from: https://www.earth.com/plant-encyclopedia/Bryophytes/Ricciaceae/riccia-glauca/en/
Ricciaceae family and the Marchantiophyta phylum. In this blog post, we’ll dive into the details of this fascinating moss species.
Background on Riccia Moss
Riccia glauca var. major is a type of thallose liverwort, meaning it has a flattened, leaf-like body called a thallus rather than true leaves like other plants. It is part of the Marchantiopsida class of liverworts. This moss is found in many parts of the world, from Europe to Asia to North America.

A-sequence-of-pictures-of-a-dense-rosette-of-Riccia-glauca-collected-in-Austria-Styria.jpg from: https://www.researchgate.net/figure/A-sequence-of-pictures-of-a-dense-rosette-of-Riccia-glauca-collected-in-Austria-Styria_fig3_357272748
Morphology and Identification
Identifying Riccia glauca var. major requires a close look, as an individual plant is only 2-5 mm wide. The thallus is thick and fleshy with a prominent midrib. The upper surface is

6c8ed778587f445e6628a8abd1b71a68.jpg from: https://www.asturnatura.com/fotografia/flora/riccia-glauca-1/27378.html
grayish-green while the underside is purplish. Tiny rhizoids anchor the plant to its substrate. Gemmae cups

206523.jpg from: https://inpn.mnhn.fr/espece/cd_nom/6218
containing asexual reproductive structures may be visible on the thallus surface.
Global Distribution and Habitat
Riccia glauca var. major has a wide distribution, found on every continent except Antarctica. It grows in a variety of habitats including:
- Moist soil along streams and rivers
- Exposed mud flats
- Damp rock crevices
- Disturbed areas like agricultural fields
This adaptable moss can tolerate periods of drying out and quickly regenerates from gemmae or thallus fragments when moisture returns.

934f50f19b11d77b4ee173034b5f6d4b.jpg from: https://www.asturnatura.com/fotografia/flora/riccia-glauca-2/27379.html
Ecological Roles and Adaptations
Despite its small size, Riccia plays important ecological roles:
- Helps prevent soil erosion by stabilizing bare ground
361_Riccia_glauca_2010_08_20_img_7320.jpg from: https://www.bryo.cz/index.php?p=mechorosty_foto&gallery=riccia_glauca&id=361
- Provides shelter and moisture for microorganisms
- Acts as a pioneer species, allowing other plants to establish
- Serves as food for some invertebrates

jd_20110213_050.jpg from: https://www.diversitasnaturae.be/diversitas-naturae/plantae/bryophyta/marchantiopsida/marchantiales/ricciaceae/riccia-glauca/
Riccia glauca var. major has several adaptations that allow it to thrive:
- Thick, leathery thallus resists drying out
- Rhizoids anchor it in place during water flow
- Gemmae allow quick dispersal and regeneration
- Protective scales and mucilage prevent UV damage
Conclusion

362_Riccia_glauca_2010_08_30_img_7877.jpg from: https://www.bryo.cz/index.php?p=mechorosty_foto&site=en&gallery=riccia_glauca&id=362
The diminutive Riccia glauca var. major moss may be easily overlooked, but it is a remarkable and important plant. From binding soil particles to enabling other species to take hold, this cosmopolitan moss plays an outsized role in the ecosystems it inhabits. Next time you’re out in nature, take a closer look – you just might spot some Riccia making a big impact!

3179481.jpg from: https://waarnemingen.be/species/17791/