Sirogonium

Sirogonium is a genus of filamentous charophyte green algae of the order Spirogyrales. It is found in freshwater areas on all continents but Antarctica. Spirogyra measures approximately 32Ã¢ÂÂ115 ÃÂ¼m in width. Each cell contains 2Ã¢ÂÂ10 chloroplasts in a ribbon, in contrast to the closely related genus Spirogyra, which has chloroplasts in a coil. Molecular phylogenetic studies have placed Sirogonium inside a clade consisting of Spirogyra species; in other words, Spirogyra is paraphyletic with respect to Sirogonium.

Species

The following species are currently accepted:

Sirogonium calosporum Zhu
Sirogonium ceylanicum Wittrock
Sirogonium decoratum Prescott
Sirogonium denticulatum W.J.Zhu
Sirogonium floridanum (Transeau) G.M.Smith
Sirogonium fuscosporum Woodhead & Tweed
Sirogonium guangzhouense Zhu
Sirogonium hui (L.C.Li) Transeau
Sirogonium illinoisense (Transeau) G.M.Smith
Sirogonium indicum Singh
Sirogonium inflatum Dixit
Sirogonium kamatii Kadlubowska
Sirogonium khoriense Masud-ul-Hassan & M.Nizamuddin

Sirogonium melanosporum (Randhawa) Transeau
Sirogonium phacosporum Skuja

Sirogonium pseudofloridanum (Prescott) Transeau
Sirogonium reticulatum Randhawa
Sirogonium retroversum H.C.Wood
Sirogonium sticticum (Smith) KÃÂ¼tzing

Sirogonium vandalurense Iyengar
Sirogonium ventersicum Transeau

References

John Whitton, B.A. and Brook, A.J. (editors) 2002. The Freshwater Algal Flora of the British Isles. Cambridge University Press, Cambridge. .