Spirotaenia is a genus of basal unicellular green algae that may be sister to the Chlorokybophyceae.

[1][2] It was previously considered to be part of the Zygnemataceae.

It is sexually conjugating, a mode of reproduction that was previously only known in the Zygnemataceae/Mesotaeniaceae, the sister groups to the land plants.

[further explanation needed][3][4] Spirotaenia may actually be more than one distinct lineage which may not be closely related.

[5] Palmophyllophyceae (prasinophyte clade VI) Prasinodermophyceae Chlorophyta Mesostigmatophyta:Mesostigmatophyceae Chlorokybophyceae Spirotaenia Klebsormidiophyceae Charophyceae Coleochaetophyceae Zygnematophyceae Embryophytes This green algae-related article is a stub.