Spirotaenia

Superregnum: Eukaryota
Regnum: Plantae
Divisio: Charophyta
Classis: Zygnematophyceae
Ordo: Zygnematales

Familia: Mesotaeniaceae
Genus: Spirotaenia
Species: S. condensata - S. obscura
Name

Spirotaenia Brébisson ex Ralfs 1848
References

Ralfs, J. 1848. The British Desmidieae. The drawings by Edward Jenner, A.L.S. pp. [i]–xxii, [i], [1]–226, 35 pls. London: Reeve, Benham & Reeve. BHL Reference page.
Croasdale & Flint: Flora of New Zealand: Desmids Vol 1 (1986)

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. This is surprising, as Spirotaenia is much more basal. The conjugating process is substantially aberrant. [3][4] Spirotaenia may actually be more than one distinct lineage which may not be closely related.[5]
Phylogeny

References

Gitzendanner, Matthew A.; Soltis, Pamela S.; Wong, Gane K.-S.; Ruhfel, Brad R.; Soltis, Douglas E. (2018). "Plastid phylogenomic analysis of green plants: A billion years of evolutionary history". American Journal of Botany. 105 (3): 291–301. doi:10.1002/ajb2.1048. ISSN 0002-9122. PMID 29603143.
Hidden genetic diversity in the green alga Spirogyra (Zygnematophyceae, Streptophyta)
Brook, Alan J. (1981). The Biology of Desmids. University of California Press. ISBN 9780520042810.
Gontcharov, Andrey A.; Melkonian, Michael (2004). "Unusual position of the genus Spirotaenia (Zygnematophyceae) among streptophytes revealed by SSU rDNA and rbcL sequence comparisons". Phycologia. 43 (1): 105–113. CiteSeerX 10.1.1.539.2139. doi:10.2216/i0031-8884-43-1-105.1. ISSN 0031-8884. S2CID 51945556.
COESEL, PETER; VANHOOF, ANDRÉ; MEESTERS, KOOS (2017-12-01). "Zygospore morphology in the conjugating green alga Spirotaenia diplohelica (Streptophyta, Zygnematophyceae, Mesotaeniaceae)". Phytotaxa. 329 (3): 284. doi:10.11646/phytotaxa.329.3.10. ISSN 1179-3163.