Riccia nigrella

Riccia nigrella
Phylum: Marchantiophyta
Family: Ricciaceae
Genus: Riccia
Common NameBlack Crystalwort
© Jack Bindernagel
iNaturalist
© Jack Bindernagel
iNaturalist
© Dan Tucker
iNaturalist
© Dan Tucker
iNaturalist
© Jack Bindernagel
iNaturalist
© Brian Starzomski
iNaturalist

Distinguishing Features

The relatively narrow thallus segments of R. nigrella are the first indication that this is not like other regional species of Riccia. The clincher requires inspecion of the edges of the thallus, which are black. When the thallus dries out, these black margins fold over, hiding much of the green upper surface of the thallus and leaving the soil marked with black, dichotomizing glyphs.

Similar species

The black margins of R. nigrella distinguish it from all other Riccia in the Pacific Northwest. Riccia campbelliana can have purple scales along the margin, but the upper surface of the thallus in that species is fringed orange, while in R. nigrella, it is green throughout.

Habitat

Associated species

Gemmabryum barnesii, Pottia truncata, Riccia beyrichiana, Riccia trichocarpa (Riccia crinita), Riccia cavernosa, Pleuridium acuminatum, Philonotis fontana

Distribution Map

Relevant Literature