Riccia frostii
Marchantiophyta
Riccia frostii (Ricciaceae)
Frost’s crystalwort
Blood Red Riccia Coins
Infrequent
Distinguishing Features
An infrequent species that forms massive populations on seasonally exposed lake and river margins, R. frostii forms 1-2cm wide red and green rosettes with a perforated upper surface at maturity. The thallus segments are typically narrow and fork apart and fit together in an orderly fashion, giving the rosettes a circular, coin-shaped appearance. Male plants are a bright, bloody red and the female plants a less-dramatic green.
Similar species
No other regional species shows the bright red colour of the male plants. Female plants could be mistaken for co-occurring R. cavernosa or R. glauca, but both those species lack the coin-shaped rosettes of R. frostii.
Habitat
Moist to wet mineral soils of riverbanks and lake margins from low elevation to steppe and montane zones; infrequent in sw, sc BC.
Associated species
Phascum cuspidatum, Riccia cavernosa, Ricciacarpos natans, Ephemerum serrulatum, Physcomitrella patens