Spirogyra is classified under Chlorophyta due to the presence of chlorophyll. The vegetative structure of Spirogyra shows as unbranched filamentous thallus. The thallus is multicellular with each cylindrical cell joined end to end. They are 10-100 µm in width and may grow several centimetres in length.

Green Algae Selection Pressures and Drivers Morphology Spirogyra Life Cycle Full Life Cycle Diagram Summary of Characteristics for Green Algae Summary Attributions Learning Objectives Distinguish between different groups of algae using life cycle, morphological features, and cellular composition.

spirogyra. a filamentous green algae characterized by spiral chloroplasts; the filaments form during asexual reproduction when mitotic division causes the haploid cells to attach end to end. fragmentation. spirogyra reproduces asexually by mitosis and ___________. conjugation tubes.