C. König [1805, Ann. Bot. (C. König & Sims), 2 : 95] (Posidoniaceae), nom. cons. vs. Alcyonium Hill in Scott [1753, Suppl. Chamber's Cyclop.] [nom. invalid.] et Alga Boehmer in Ludwig [1760. Def. Gen., ed. 3 : 503], nom. rej. (Alga, Caulinia, Kernera, Zostera) T : P. caulini