Discostella Guide
Credit: Rex Lowe
  1. Central area with large alveoli, often star-shaped
  2. Marginal radial costae
  3. Marginal fultoportulae present

Discostella grows as solitary cells or forms colonies in chains. The central area may be flat or concentrically undulate. Large, distinctive alveoli form a star-shaped pattern in the central valve. Radial costae are present at the valve margin. Small spines may be present or absent on the costae. Central to the costae are striae, which may be uniseriate or multiseriate. Marginal fultoportulae are present, located on every few striae. A single rimoportula is positioned on the margin of the valve, between two costae.

Discostella contains the 'stelligeroid' Cyclotella sensu lato species, and includes D. stelligera, D. pseudostelligera, D. woltereckii, D. glomerata, D. stelligeroides. In general, the group is widespread in planktonic habitats.