Phylum: Charophyta Family: Gonatozygaceae
Gonatozygon brebissonii var. minutum (West) West & G.S. West
As the name suggests, this is a small version of the nominate variety. It also differs in having a much-reduced cell-wall profile. It is mainly covered in small granules and rarely developing into short spines. It also differs in liking less acidic habitats such as ephemeral pools. It would appear to be much scarcer than the nominate.
Brook, A.J. & Williamson, D.B. (2010) A Monograph on some British Desmids
West, W. & West, G.S. (1904) A Monograph of the British Desmidiaceae, Volume 1
Ružicka, J. (1977) Die Desmidiaceen Mitteleuropas, Volume 1, Part 1