Phylum: Charophyta   Family: Desmidiaceae

Staurastrum muticum morpha 

For a relatively small desmid, St. muticum has a considerable size-range, especially now forma minus Rabenhorst 1868 has been subsumed into the nominate variety. It is likely that more than one taxon is involved. The smallest dimension recorded for that species is about 15 µm in length. This taxon under discussion is even smaller and it would be pushing the boundaries even further to annex it to St. muticum. It also differs in being slightly broader than long, whereas St. muticum is about as long as broad. I currently regard this as an undescribed species.
Cell dimensions (2): L: 12.6-13 µm; B: 14.6-14.7 µm; Is: 7.4-7.5 µm; L/B: 0.86-0.89.
Found in an acidic habitat with Sphagnum and algal sludge.

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