Phylum: Charophyta Family: Desmidiaceae
Cosmarium askernishense C.D.N. Johnson 2023
This new species has been published in Desmidiological Communications (2023, Issue 10, pp. 16-19).
Cells 1.25–1.37 times longer than broad with an acute, open sinus from the start. Semicells somewhat variable in outline, in frontal view broadly trapeziform with the lower lateral angle straight to marginally convex running smoothly into rounded lateral angles, the broadest part of the semicell about one third up from the isthmus. Upper laterals are slightly convex running smoothly into the apex which is also slightly convex. The cell wall is quite thick and uniformly and densely punctate (mucus pores). There is noticeable cell-wall thickening at the widest points and, less so, at the apex. In side view the semicells are orbicular with a lenticular wall thickening. The apical view is broadly ellipsoid with rather narrowly rounded poles and a considerable, broad wall thickening on either frontal side. Chloroplast axile with a single large pyrenoid per semicell. Zygospore unknown.
Complete taxonomic description: Cosmarium askernishense
Johnson, C.D.N. (2023) Descriptions of two previously undescribed species from the Outer Hebrides, Scotland, UK. Desmidiological Communications 10