Desmidiales

Desmidiales, commonly called the desmids (Gr. desmos, bond or chain), are an order in the Charophyta, a division of green algae in which the land plants (Embryophyta) emerged. Desmids consist of single-celled (sometimes filamentous or colonial) microscopic green algae. Because desmids are highly symmetrical, attractive, and come in a diversity of forms, they are popular subjects for microscopists, both amateur and professional.

The desmids belong to the class Zygnematophyceae. Although they are sometimes grouped together as a single family Desmidiaceae, most classifications recognize three to five families, usually within their own order, Desmidiales.