Cystophyllum thunbergii (Mertens ex Roth) J.Agardh Dataset GBIF Backbone Taxonomy Rank SPECIES Classification kingdom Chromista phylum Ochrophyta class Phaeophyceae order Fucales family Sargassaceae genus Sargassum species Sargassum thunbergii Name Homonyms Cystophyllum thunbergii (Mertens ex Roth) J.Agardh