Phylum: Charophyta Family: Desmidiaceae
Xanthidium antilopaeum var. planum Roll 1936
Differs from the nominate variety in having the spines curved downwards; it's much scarcer. Found in similar habitats of acidic bogs and vegetated lochan.
References:
Stastny, J., et al (2013) Polyphasic evaluation of Xanthidium antilopaeum and Xanthidium cristatum (Zygnematophyceae, Streptophyta) species complex.
Coesel, P.F.M. & Meesters, K.J. (2007) Mesotaeniaceae and Desmidiaceae of the European Lowlands.