Phylum: Charophyta   Family: Desmidiaceae

Cosmarium subspeciosum var. validius Nordstedt 1887

This variety is somewhat larger than the nominate, first named by Nordstedt (1887). It has a widespread Arctic-alpine distribution but has also been found in New Zealand (Croasdale & Flint 1988). At present it's regarded as rare but there is much confusion with the nominate variety and other similar forms.

References: 
Nordstedt, C.F.O. (1887) Algologiska småsker. 4. Ukdrag ur ett arbete öfver de af Dr. S. Berggren på Nya Sealand och i Australien Samlade sötvàttebsakgerna.
Croasdale, H. & Grönblad, R. (1964) Desmids of Labrador 1. Desmids of the southeastern coastal area.
Lenzenweger, R. (1999) Desmidiaceenflora von Österreich, Teil 3.
Croasdale, H. & Flint, E.A. (1988) Flora of New Zealand: Desmids, Volume 2.
Kouwets, F.A.C. (in manuscript) European Flora of the Desmid Genus Cosmarium.