These organisms have a multicellular, filamentous structure surrounded by a mucilaginous sheath. They contain 2-10 spiral and ribbon-shaped chloroplasts, each with numerous pyrenoids. Ranging from 10-100 µm in width, they can grow several centimeters in length. Their cell wall consists of two layers: inner cellulose and outer pectose. The presence of a mucilage sheath renders them as a slimy mass. They undergo vegetative, asexual, and sexual reproduction processes.