Spirogyra is a genus of filamentous charophyte green algae of the order Zygnematales, named for the helical or spiral arrangement of the chloroplasts that is diagnostic of the genus. It is commonly found in freshwater areas, and there are more than 400 species of Spirogyra in the world. Spirogyra measures approximately 10 to 100μm in width and ma... Found on http://en.wikipedia.org/wiki/Spirogyra
genus of green algae, found only in fresh water and usually free-floating. The slippery unbranched filaments are composed of cylindrical cells ... [1 related articles] Found on http://www.britannica.com/eb/a-z/s/142