Phylum: Charophyta   Family: Gonatozygaceae

Gonatozygon brebissonii var. vulgare M. Raciborski 1885

First described and illustrated by Raciborski (1885: 67, pl. 5). It differs from the nominate variety in being less attenuated and the apices are not so capitate or thickened. It is smaller in length than the nominate variety and has small granules instead of spines. Some cells can appear a bit distorted as they undergo division. At least one of the images below show two nuclei. The zygospore is orbicular and smooth-walled, but rarely found.
Cell dimensions: L: 60-93 µm; B: 5.7-6.7 µm; L/B: 9-16.
Zygospore: Diameter: c.21 µm.
This seemingly rare taxon prefers neutral to slightly alkaline habitats such as ephemeral pools.

References: 
Brook, A.J. & Williamson, D.B. (2010) A Monograph on some British Desmids.
Raciborski, M. (1885) Opisy nowych desmidyjów polskich. De nonnullis Desmidiaceis novis vel minus cognitis quae in Polonia inventae sunt.
Ruzicka, J. (1977) Die Desmidiaceen Mitteleuropas, Volume 1, Part 1.