Spirogyra

Spirogyra in the conjugation

Spirogyra ( " Schraubenalge " ) is a genus of green algae. It belongs to the family of Zygnemataceae. The thread-like ( filamentous ) Spirogyra often in calm waters occurs in spring as free-floating, filamentous, bright green " cotton " on.

It is one of the Jochalgen (multiplication by Jochbildung ), and has no flagellated stages. The chloroplast is spirally wound (hence the name Spirogyra ).

A special ability of Zygnemataceae is to be able to also utilize the ionic bicarbonate for photosynthesis scarcity of dissolved carbon dioxide. They give off hydroxide so that the pH of the water in the vicinity of the algae cotton may rise to values ​​to 11.

Fossils of this genus are known from the Carboniferous.