'green plants'; kingdom Plantae sensu stricto)[6] is a clade of around 450,000–500,000 species of eukaryotic organisms, most of which obtain their energy by photosynthesis.

The green plants are chloroplast-bearing autotrophs that play important primary production roles in both terrestrial and aquatic ecosystems.

[18] Together with Rhodophyta, glaucophytes and other basal groups, Viridiplantae belong to a larger clade called Archaeplastida which in itself is sometimes described as Plantae sensu lato.

[22][23] The classification of Bryophyta is supported both by Puttick et al. 2018,[24] and by phylogenies involving the hornwort genomes that have also since been sequenced.

Mesostigmatophyceae Chlorokybophyceae Spirotaenia Klebsormidiales Chara Coleochaetales Zygnematophyceae Hornworts Liverworts Mosses Lycophytes Ferns Gymnosperms Angiosperms Ancestrally, the green algae were flagellates.