Mesotaeniaceae
The Mesotaeniaceae are a small family of unicellular green algae known as the "saccoderm desmids". The Mesotaeniaceae appear to be sister or ancestral to the Zygnemataceae. The desmids are a deep branching group of Zygnemataceae. Spirotaenia was found to be a basal green alga.
Genera
The Mesotaeniaceae includes the following genera:Ancylonema Berggren, 1872Cylindrocystis Meneghini ex De Bary, 1858Geniculus Prescott, 1967Mesotaenium Nägeli, 1849Netrium Itzigsohn & Rothe, 1856Nucleotaenium Gontcharov & Melkonian, 2010Planotaenium Petlovany & Palamar-Mordvintseva, 2009Roya West & G.S.West, 1896Tortitaenia A.J.Brook, 1998Synonyms:Endospira Brébisson, nom. inval., is a synonym of SpirotaeniaEntospira Kuntze, 1898 is a synonym of SpirotaeniaPolytaenia A.J.Brook, 1997, nom. illeg., is a synonym of ''Tortitaenia''