Phylum: Charophyta   Family: Desmidiaceae

Xanthidium robinsonianum W. Archer

A rare species first recorded from western Ireland, with most later records from Shetland and Sutherland. It was first recorded from the Outer Hebrides in 2019 from a loch margin. Later finds have been from slightly acidic disused peat-cuttings.

References: 
John, D.M. & Williamson, D.B. (2009) A Practical Guide to the Desmids of the West of Ireland
West, W. & West, G.S. (1912) A Monograph of the British Desmidiaceae, Volume 4