Homoeocladia sigmoidea (Nitzsch) Elmore Dataset GBIF Backbone Taxonomy Rank SPECIES Classification kingdom Chromista phylum Ochrophyta class Bacillariophyceae order Bacillariales family Bacillariaceae genus Nitzschia species Nitzschia sigmoidea Name Homonyms Homoeocladia sigmoidea (Nitzsch) Elmore, 1921 Homoeocladia sigmoidea W.Smith, 1856