Alga Ludw. Dataset GBIF Backbone Taxonomy Rank GENUS Published in Def. (1737) 138, fide Kuntze. Classification kingdom Plantae phylum Tracheophyta class Liliopsida order Alismatales family Posidoniaceae genus Alga Name Homonyms Alga Boehm. Alga Adanson, 1763 Alga Tourn. ex Lam. Alga Ludw.