Viridiplantae

Viridiplantae (literally "green plants")[5] are a clade of eukaryotic organisms that comprise approximately 450,000–500,000 species and play important roles in both terrestrial and aquatic ecosystems.[6] They are made up of the green algae, which are primarily aquatic, and the land plants (embryophytes), which emerged from within them.[7][8][9] Green algae traditionally excludes the land plants, rendering them a paraphyletic group. However it is accurate to think of land plants as a kind of algae.[10] Since the realization that the embryophytes emerged from within the green algae, some authors are starting to include them.[10][11][12][13][14] They have cells with cellulose in their cell walls, and primary chloroplasts derived from endosymbiosis with cyanobacteria that contain chlorophylls a and b and lack phycobilins.

Viridiplantae
An assortment of thallophyte Viridiplantae in a rock pool, Taiwan
Scientific classification
Domain:	Eukaryota
(unranked):	Diaphoretickes
(unranked):	Archaeplastida
(unranked):	Viridiplantae Cavalier-Smith, 1981
Subgroups
Prasinodermophyta Chlorophyta Streptophyta Mesostigmatophyceae Chlorokybophyceae Spirotaenia streptofilum Klebsormidiophyceae Charophyceae Coleochaetophyceae Zygnematophyceae Embryophyta
Synonyms
Plantae, Copeland, 1938, 1956[1][2] Euchlorophyta Whittaker, 1969[3] Chlorophyta sensu van den Hoek & Jahns, 1978[4] Chlorobionta Jeffrey 1982, emend. Bremer 1985, emend. Lewis and McCourt 2004 Chlorobiota Kendrick and Crane 1997 Chloroplastida Adl et al., 2005 Viridiplantae Cavalier-Smith 1981[5] Phyta Barkley 1939 emed. Holt & Uidica 2007 Cormophyta Endlicher, 1836 Cormobionta Rothmaler, 1948 Euplanta Barkley, 1949 Telomobionta Takhtajan, 1964 Embryobionta Cronquist et al., 1966 Metaphyta Whittaker, 1969

In some classification systems, the group has been treated as a kingdom,[15] under various names, e.g. Viridiplantae, Chlorobionta, or simply Plantae, the latter expanding the traditional plant kingdom to include the green algae. Adl et al., who produced a classification for all eukaryotes in 2005, introduced the name Chloroplastida for this group, reflecting the group having primary chloroplasts with green chlorophyll. They rejected the name Viridiplantae on the grounds that some of the species are not plants, as understood traditionally.[16] The Viridiplantae are made up of two clades: Chlorophyta and Streptophyta as well as the basal Mesostigmatophyceae and Chlorokybophyceae.[17][18] Together with Rhodophyta and glaucophytes, Viridiplantae are thought to belong to a larger clade called Archaeplastida or Primoplantae.

A taxonomic evaluation of eukaryotes based on myosin distribution showed the Viridiplantae lost class-I myosins.[19]