Green algae

For an explanation of its other names, see Viridiplantae and Plantae.
For the bacteria commonly known as blue-green algae that can produce toxic blooms in lakes and other waters, see Cyanobacteria.

Green algae
PicocystophyceaeTrebouxiophyceaeKlebsormidiophyceaeZygnematophyceaeUlvophyceaeChlorophyceaeCharophyceaeDesmid
Green algal diversity. From top left corner: Picocystis (Picocystophyceae), Acetabularia (Ulvophyceae), Botryococcus (Trebouxiophyceae), Volvox (Chlorophyceae), Klebsormidium (Klebsormidiophyceae), Chara (Charophyceae), Spirogyra and Micrasterias (Zygnematophyceae)
Scientific classificationEdit this classification
Clade: Archaeplastida
Clade: Viridiplantae
Groups included
Cladistically included but traditionally excluded taxa

The green algae (sg.: green alga) are a group of chlorophyll-containing autotrophic eukaryotes consisting of the phylum Prasinodermophyta and its unnamed sister group that contains the Chlorophyta and Charophyta/Streptophyta. The land plants (Embryophytes) have emerged deep in the Charophyte alga as a sister of the Zygnematophyceae.[1][2][3] Since the realization that the Embryophytes emerged within the green algae, some authors are starting to include them.[2][4][5][6][7][excessive citations] The completed clade that includes both green algae and embryophytes is monophyletic and is referred to as the clade Viridiplantae and as the kingdom Plantae. The green algae include unicellular and colonial flagellates, most with two flagella per cell, as well as various colonial, coccoid (spherical), and filamentous forms, and macroscopic, multicellular seaweeds. There are about 22,000 species of green algae,[8] many of which live most of their lives as single cells, while other species form coenobia (colonies), long filaments, or highly differentiated macroscopic seaweeds.

A few other organisms rely on green algae to conduct photosynthesis for them. The chloroplasts in dinoflagellates of the genus Lepidodinium, euglenids and chlorarachniophytes were acquired from ingested endosymbiont green algae,[9] and in the latter retain a nucleomorph (vestigial nucleus). Green algae are also found symbiotically in the ciliate Paramecium, and in Hydra viridissima and in flatworms. Some species of green algae, particularly of genera Trebouxia of the class Trebouxiophyceae and Trentepohlia (class Ulvophyceae), can be found in symbiotic associations with fungi to form lichens. In general the fungal species that partner in lichens cannot live on their own, while the algal species is often found living in nature without the fungus. Trentepohlia is a filamentous green alga that can live independently on humid soil, rocks or tree bark or form the photosymbiont in lichens of the family Graphidaceae. Also the macroalga Prasiola calophylla (Trebouxiophyceae) is terrestrial,[10] and Prasiola crispa, which live in the supralittoral zone, is terrestrial and can in the Antarctic form large carpets on humid soil, especially near bird colonies.[11]

  1. ^ Cite error: The named reference HuanLiu-2020 was invoked but never defined (see the help page).
  2. ^ a b Delwiche CF, Timme RE (June 2011). "Plants". Current Biology. 21 (11): R417–22. doi:10.1016/j.cub.2011.04.021. PMID 21640897.
  3. ^ Palmer JD, Soltis DE, Chase MW (October 2004). "The plant tree of life: an overview and some points of view". American Journal of Botany. 91 (10): 1437–45. doi:10.3732/ajb.91.10.1437. PMID 21652302.
  4. ^ "Charophycean Green Algae Home Page". www.life.umd.edu. Retrieved 2018-02-24.
  5. ^ Cite error: The named reference Ruhfel-2014 was invoked but never defined (see the help page).
  6. ^ Delwiche CF, Cooper ED (October 2015). "The Evolutionary Origin of a Terrestrial Flora". Current Biology. 25 (19): R899–910. doi:10.1016/j.cub.2015.08.029. PMID 26439353.
  7. ^ Parfrey LW, Lahr DJ, Knoll AH, Katz LA (August 2011). "Estimating the timing of early eukaryotic diversification with multigene molecular clocks". Proceedings of the National Academy of Sciences of the United States of America. 108 (33): 13624–9. Bibcode:2011PNAS..10813624P. doi:10.1073/pnas.1110633108. PMC 3158185. PMID 21810989.
  8. ^ Guiry MD (October 2012). "How many species of algae are there?". Journal of Phycology. 48 (5): 1057–63. doi:10.1111/j.1529-8817.2012.01222.x. PMID 27011267. S2CID 30911529.
  9. ^ Jackson, Christopher; Knoll, Andrew H.; Chan, Cheong Xin; Verbruggen, Heroen (2018). "Plastid phylogenomics with broad taxon sampling further elucidates the distinct evolutionary origins and timing of secondary green plastids". Scientific Reports. 8 (1): 1523. Bibcode:2018NatSR...8.1523J. doi:10.1038/s41598-017-18805-w. PMC 5784168. PMID 29367699.
  10. ^ Holzinger, A.; Herburger, K.; Blaas, K.; Lewis, L. A.; Karsten, U. (2017). "The terrestrial green macroalga Prasiola calophylla (Trebouxiophyceae, Chlorophyta): Ecophysiological performance under water-limiting conditions". Protoplasma. 254 (4): 1755–1767. doi:10.1007/s00709-016-1068-6. PMC 5474099. PMID 28066876.
  11. ^ Carvalho, Evelise L.; MacIel, Lucas F.; MacEdo, Pablo E.; Dezordi, Filipe Z.; Abreu, Maria E. T.; Victória, Filipe de Carvalho; Pereira, Antônio B.; Boldo, Juliano T.; Wallau, Gabriel da Luz; Pinto, Paulo M. (2018). "De novo Assembly and Annotation of the Antarctic Alga Prasiola crispa Transcriptome". Frontiers in Molecular Biosciences. 4: 89. doi:10.3389/fmolb.2017.00089. PMC 5766667. PMID 29359133.