[2] Pediastrum duplex forms nonmotile coenobia (colonies) with a fixed number of cells.

The cells are polygonal, distinctly rectangular in outline with concave sides.

[4] It reproduces by forming autocolonies asexually, although sexual reproduction has also been observed.

[5] Pediastrum duplex is a very common component of the freshwater phytoplankton, and has a cosmopolitan distribution.

subgranulatum Raciborski[6][7] One variety, Pediastrum duplex var.

gracillimum, has been shown to be not closely related to Pediastrum duplex sensu stricto.