Desmid

The Zygnematales (Greek: ζυγός (zygós) and νῆμα (nḗma) (nom.), νήματος (nḗmatos) (gen.)), also called the Conjugatales, are an order of green algae, comprising several thousand different species in two families. The larger family Zygnemataceae, with well-known genera such as Zygnema and Spirogyra, includes members that grow as unbranched filaments, which grow longer through normal cell division. The smaller family Mesotaeniaceae includes the saccoderm "desmids", a group of unicellular species that were formerly classified with the "true"...