Riccia cavernosa Hoffm. emend. Raddi

Hugonnot, Vincent, 2019, New records for the bryophyte flora of Corsica, Cryptogamie, Bryologie 20 (14), pp. 153-158 : 155

Riccia cavernosa Hoffm. emend. Raddi

SPECIMEN EXAMINED. — France. Corse-du-Sud, Bonifacio, mare temporaire de Musella, 26 IV.2017, 54 m a.s.l., V. Hugonnot s.n.

Remarks

It was observed within a mediterranean temporary pond of great floristic interest ( Lorenzoni & Paradis 1998), in which Eryngium pusillum L. was also found. Both species may share comparable ecological requirements. The associated vegetation is considered to be part of Trifolio-Cynodontion Br.-Bl. & O. Bolòs, 1957. Riccia cavernosa grew directly on wet mud. It seems to suffer from overgrazing of the site which causes severe trampling and direct destruction of vegetation. In the Mediterranean, it was recorded in occasionally to periodically flooded ditch banks, soils depressions and margins of temporary ponds ( Jovet-Ast 1986). The thalli observed in Corsica were poorly developed and sterile.

Riccia cavernosa is a Circumpolar-temperate taxon ( Düll 1983). At a world scale it is recorded in northern, western, central and eastern Europe, northern and central Asia, tropical and southern Africa, North, Central and South America and Australasia ( Bischler 2004). In the Mediterranean Region its distribution includes Canary Islands, Cape Verde Islands and Madeira in Macaronesia; Balearic Islands, Croatia, France, Italy, Portugal, Sicily and Spain in southern Europe; as well as Algeria, Egypt, Libya, Morocco and Tunisia in northern Africa ( Bischler 2004; Patiño Llorente & González Mancebo 2005; Ros et al. 2007). In Mediterranean France, the species is known in the Departments of Pyrénées-Orientales ( Hugonnot et al. 2017), Hérault ( Crozals 1903) and Bouches-du-Rhône ( Hébrard et al. 2014).