Although it was once placed in the family Volvocaceae,[2] it is not closely related to them; its sister is the unicellular genus Balticola.

[4] Stephanosphaera pluvialis forms colonies of four or eight cells, arranged in a ring and surrounded by a spherical matrix.

Cells contain several contractile vacuoles, a rounded stigma, and a single large parietal chloroplast with usually two pyrenoids.

Asexual reproduction occurs by autocolony formation: a cell divides until it becomes like a miniature version of the existing colony, and the new colony is released from the cell.

It tends to occur in rainwater puddles on non-basic rocks, more rarely in lakes.