Phylum: Charophyta   Family: Desmidiacea

Cosmarium sp. North Tolsta 

Semicells depressed semicircular in outline, deeply constricted; sinus linear and slightly dilate at the apex. Basal angle tightly rounded with a pronounced papillate granule, sides convex and merging with the rounded to truncate apex. Cell-wall covered with small to medium granules with 10-12 visible on each side of the semicell. Apical view elliptic, lateral view circular. Chloroplast axile with two pyrenoids. Zygospore unknown.
Cell dimensions: L: 55.7-59.4 µm; B: 47.2-48.2 µm; Is: 17.5-18.1 µm; Th: c.30 µm; L/B: 1.18-1.24.
It bears some resemblance to C. smolandicum with the papilla at the basal angles, but that species is completely smooth walled.
Collected from squeezed mosses from dripping rocks in a stable dune system.

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