Order Charales, also known as stoneworts, is a group of green algae commonly found in freshwater habitats. They are mainly characterized by their calcified cell walls and branched, filamentous structure. When referring to these green algae, other common synonyms used include Charophytes, Charophyta, and Charales. These synonyms are useful when talking about the same group of organisms without repeating the same term. For instance, researchers may use these synonyms to make distinctions between different classes, such as Charophyceae, and Zygnematophyceae, which straddle the taxonomy of Charales. Using these synonyms helps to clarify and avoid confusion when discussing the group.