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 Gonatozygaceae
         Genus Roya West & G.S.West (1896)
           1 Roya anglica G.S.West (1920)