Green Algae - Classification

Classification

Green algae are often classified with their embryophyte descendants in the green plant clade Viridiplantae (or Chlorobionta). Viridiplantae, together with red algae and glaucophyte algae, form the supergroup Primoplantae, also known as Archaeplastida or Plantae sensu lato.

Classification systems which have a kingdom of Protista may include green algae in the Protista or in the Plantae.

Phylogeny:

The orders outside the Chlorophyta are often grouped as the division Charophyta, which is paraphyletic to higher plants, together comprising the Streptophyta. Sometimes the Charophyta is restricted to the Charales, and a division Gamophyta is introduced for the Zygnematales and Desmidiales. In older systems the Chlorophyta may be taken to include all the green algae, but taken as above they appear to form a monophyletic group.

One of the most basal green algae is the flagellate Mesostigma, although it is not yet clear whether it is sister to all other green algae, or whether it is one of the more basal members of the Streptophyta.