Welcome back to another "What Is It?" episode of Algae Corner! On this episode, we're talking about silk algae, or spirogyra.
Spyrogyra is a filamentous desmid in the streptophyte phyla, with spiraling chloroplasts that grow around the cell. It's sort of slippery feeling, hence the name silk algae.
The reason it feels this way is because it has this extra-cellular cell wall made mostly of pectin.