Phaeocephalum album subsp. marcum Farw. Dataset GBIF Backbone Taxonomy Rank SUBSPECIES Classification kingdom Plantae phylum Tracheophyta class Liliopsida order Poales family Cyperaceae genus Rhynchospora species Rhynchospora alba Name Homonyms Phaeocephalum album var. marcum (C.B.Clarke ex Britton) Farw. Phaeocephalum album subsp. marcum Farw.