Phylum: Charophyta Family: Desmidiaceae
Cosmarium pyramidatum subsp. abnorme Lütkemüller 1893
Kouwets (1987, p. 231, pl. 11: 11-12) described a population of pyramid-form cells, which were between C. pyramidatum and C. pseudopyramidatum in size and displayed three pyrenoids in most semicells. Krieger & Gerloff (1965, p. 121, pl. 25: 3) also described cells with three pyrenoids but with a large size-range suggesting more than one taxon is involved. Surprisingly, his drawing in side-view is remarkably quadrate? The population from the Wind Farm, South Uist was squeezed from Sphagnum and is similar in size to Kouwets' find with perhaps the isthmus measurements slightly broader. The pyrenoids are not always easy to see. Kouwets is proposing to raise this subspecies (his morpha) to species level [Cosmarium pyramidatiforme] but will not be accepted until published.
Lütkemüller, J. (1893) Desmidiaceen aus der Umgebung des Attersees in Oberösterreich.
Kouwets, F.A.C. (1987) Desmids from the Auvergne (France).
Krieger, W. & Gerloff, J. (1962-9) Die Gattung Cosmarium.
Kouwets, F.A.C. (in manuscript) European Flora of the Desmid Genus Cosmarium.