Freshwater Algae of North America
   Class Zygnematophyceae C.Hoek, D.G.Mann & H.M. Jahns (1995), nom. inval. - conjugating green algae see Class Zygnematophyceae Round ex Guiry (2013)
     Order Desmidiales - placoderm desmids
       Family Desmidiaceae Kützing ex Ralfs (1845)
         Genus Xanthidium Ehrenb. ex Ralfs (1848)
           1 Xanthidium armatum (Bréb.) ex Ralfs (1848)
           2 Xanthidium antilopaeum (Bréb.) ex Kütz. (1849)