Image © Marien van Westen

Another cell of Cosmarium angulare.
Scale bar is 10 µm


Image © Marien van Westen

Almost empty cell of Cosmarium angulare better showing its papillate basal semicell angles.
Scale bar is 10 µm

 

 

Desmid of the month
February 2023

Cosmarium angulare

C. angulare is a rather small, smooth-walled Cosmarium species readily to be distinguished by the hexagonal-octogonal outline of its semicells in combination with distinctly papillate basal angles. Lateral sides from basal to lateral angles are slightly divergent, then strongly convergent to the straight or slightly retuse apex. In the Netherlands, C. angulare is a rather rare species known from but a few mesotrophic sites (mainly quaking fen hollows).

Cosmarium angulare
Image © Alfred van Geest

Cosmarium angulare. Notice hexagonal-octogonal outline of semicells and papillate basal angles.
Cell dimensions (L x B): 30 x 27 µm