Equisetum affine Engelm. Dataset GBIF Backbone Taxonomy Rank SPECIES Classification kingdom Plantae phylum Tracheophyta class Polypodiopsida order Equisetales family Equisetaceae genus Equisetum species Equisetum praealtum Name Homonyms Equisetum affine Engelm. Equisetum affine (Engelm. ex Rydb) Rydb.