Desmid of the month
C. brebissonii is a large-sized, firm-lined Cosmarium species with a granulate cell wall. Semicells are about trapeziform with very broadly rounded angles. Compared with many other species meeting those features C. brebissonii is to be recognized by its remarkably stout, conical granules that are rather evenly distributed over the cell wall (not being arranged in a particular pattern). C. brebissonii is characteristic of acidic, oligo-mesotrophic bog sites. In the Netherlands it is very rare.
Image © Alfred van Geest
mouse-over image © Ton (A.M.T.J.) Joosten
Cosmarium brebissonii. Notice the large dimensions and the stout, conical granules that are rather evenly distributed over the cell wall.
Cell dimensions (L x B): 95 x 75 µm
Another cell of C. brebissonii, collected in the Czech Republic