Phylum: Charophyta   Family: Desmidiaceae

Staurastrum hirsutum var. pseudarnellii Coesel & Meesters 2013

Found in acidic oligotrophic pools and ditches. Status in the Outer Hebrides unknown.

References: 
Coesel, P.F.M. & Meesters, K.J. (2013) European Flora of the Desmid Genera Staurastrum and Staurodesmus.