Cosmarium margaritatum f. subrotundatum West & G.S.West, 1912 Dataset GBIF Backbone Taxonomy Rank FORM Classification kingdom Plantae phylum Charophyta class Conjugatophyceae order Desmidiales genus Cosmarium species Cosmarium margaritatum Name Homonyms Cosmarium margaritatum f. subrotundatum West & G.S.West, 1912 Cosmarium margaritatum var. subrotundatum (West & G.S.West) Petlovany, 2015