Bryum lacustre subsp. arnellii Kindb. Dataset GBIF Backbone Taxonomy Rank SUBSPECIES Classification kingdom Plantae phylum Bryophyta class Bryopsida order Bryales family Bryaceae genus Ptychostomum species Ptychostomum knowltonii Name Homonyms Bryum lacustre var. arnellii (Kindb.) Kindb. Bryum lacustre subsp. arnellii Kindb.