Chlorophyta is a taxonomic group belonging to the Kingdom Plantae. It may refer to a division within the Kingdom Plantae comprised of all green algal species. Later, some taxonomists classify those green algal species living predominantly in marine water as chlorophytes (i.e. belonging to Chlorophyta) whereas those green algal species thriving mainly in freshwater are classified as charophytes (i.e. belonging to Charophyta). Thus, in the first method of taxonomic classification, Chlorophyta includes about 7,000 known species of green algae. In the second sense of taxonomic classification, the Chlorophyta consists of only about 4,300 species, whereas the others initially regarded as chlorophytes are classified as charophytes.
According to Hoek, Mann and Jahns system1, an older taxonomic classification of algae, Chlorophyta is a division of Kingdom Plantae that included all green algae grouped into classes, Prasinophyceae, Chlorophyceae, Ulvophyceae, Cladophorophyceae, Bryopsidophyceae, Dasycladophyceae, Trentepohliophyceae, Pleurastrophyceae, Klebsormidiophyceae, Zygnematophyceae, and Charophyceae. In newer classification such as that of Leliaert et al.2, the charophytes are separated from the chlorophytes and belong (together with the embryophytes) to Streptophyta of Viridiplantae.
It should be noted, however, that the taxonomic classification of organisms is bound to change as further studies of the species would lead to newer system of classification, such as that in The NCBI taxonomy database.3
Word origin: Ancient Greek khlōrós (green) + -phyta (plant)
1 Hoek, C. van den, Mann, D.G. and Jahns, H.M. (1995). Algae An Introduction to Phycology. Cambridge: Cambridge University Press.
2 Leliaert, F., Smith, D.R., Moreau, H., Herron, M.D., Verbruggen, H., Delwiche, C.F. & De Clerck, O. (2012). "Phylogeny and molecular evolution of the green algae" (PDF). Critical Reviews in Plant Sciences 31: 1–46.
3 The NCBI taxonomy database. Retrieved from .