Phylum: Chlorophyta   Family: Scenedesmaceae

Desmodesmus communis (E.H. Hegewald) E.H. Hegewald 2000

First described and illustrated by Hegewald (1977: 151, figs 12-13) as Scenedesmus communis. Hegewald (2000: 8) later moved it to its current position. Supporting 2 curved spines on the outermost cells.
Cell dimensions: L: 9-17 µm; B: 3.5-6.6 µm. Coenobia 4(-8).
Fairly common in a large range of water types from acidic to alkaline

References: 
Hegewald, E.H. (1977). Scenedesmus communis Hegewald, a new species and its relation to Scenedesmus quadricauda (Turp.) Bréb.
Hegewald, E.H. (2000). New combinations in the genus Desmodesmus (Chlorophyceae, Scenedesmaceae).
John, D.M., Whitton, B.A. & Brook, A.J. (2011 second edition). The Freshwater Algal Flora of the British Isles.