No loner in genus Cladophora, the presence of silicates in Marimo algae cells differentiates them from Cladophora.
Extensive DNA research in 2002 returned the name to Aegagropila linnaei. The presence of chitin in the cell walls makes it distinct from the genus Cladophora.
The plant was named "marimo" by a Japanese botanist Tatsuhiko Kawakami (川上龍彦 Kawakami Tatsuhiko?) in 1898 (Meiji 31)
Further reading:
about MARIMO
http://aboutmarimo.blogspot.ca/2011/12/about-marimo.html
