Mesostigma viride is a species of freshwater green algae

Green algae

The green algae are the large group of algae from which the embryophytes emerged. As such, they form a paraphyletic group, although the group including both green algae and embryophytes is monophyletic...

. It is now considered to be one of the earliest diverging members of the Streptophyta, one of the two lineages of green plants (Viridiplantae

Viridiplantae

Viridiplantae are a clade comprising the green algae and land plants.In some classification systems they have been treated as a kingdom, under various names, e.g. Viridiplantae, Chlorobionta, or simply Plantae, the latter expanding the traditional Plant Kingdom to include the green algae...

).

Earlier studies were unable to resolve the position of the species, and it was often placed as a sister to all other green algae, as one of the basal members of the Streptophyta, or as close to Chaetosphaeridium

Chaetosphaeridium

Chaetosphaeridium is a genus of green algae. Although several classifications have been proposed, the bulk of the evidence supports its traditional classification in the order Coleochaetales, related to the genus Coleochaete.- Species :...

. More recent studies agree that Mesostigma and Chlorokybus form a clade

Clade

A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...

, being the earliest diverging streptophytes.

External links

• Mesostigma viride from Algaebase