From Wikipedia, the free encyclopedia
Jump to: navigation, search
Chara sp reproductive structure.JPG
Scientific classification
Domain: Eukaryota
(unranked) Archaeplastida
Kingdom: Viridiplantae
Division: Charophyta
Migula 1897
Included groups





The Charophyta are a division of freshwater green algae[1] that includes the class Charophyceae, a sister group to the terrestrial plants, the Embryophyta.[2] In some charophyte groups, such as Zygnematophyceae or conjugating green algae, flagellae are absent and sexual reproduction does not involve free-swimming flagellate sperm. Flagellate sperm, however, are found in stoneworts (Charales) and Coleochaetales, orders of parenchymous charophytes that are the closest relatives of the land plants, where flagellate sperm are also present in all except the conifers and flowering plants.[3] Fossils of a stonewort of Devonian age that are similar to those of the present day have been described from the Rhynie chert of Scotland.[4]


Charophyta are complex green algae that form a sister group to the Chlorophyta and the Embryophyta. The chlorophyte and charophyte green algae and the embryophytes or land plants form a clade called the green plants or Viridiplantae, that is united among other things by the absence of phycobilins, the presence of chlorophyll b and chlorophyll a and the use of starch as a storage polysaccharide. Charophytes and embryophytes share the same mechanism of cell division using a phragmoplast as a framework for assembly of the new dividing cell wall. Thus Charophyta and Embryophyta together form the clade Streptophyta, excluding the Chlorophyta. Because the Charophyta do not include all descendents of their common ancestor with the embryophytes they form a paraphyletic group.[5]


The charophytes are obligate aquatic algae, growing submerged in calcareous fresh water. They are distributed throughout the world from the tropics to cold temperate zones. Charophytes such as Palaeonitella cranii and possibly the yet unassigned Parka decipiens[6] are present in the fossil record of the Devonian.[4] Palaeonitella differed little from some present-day stoneworts.

The various groups included in the Charophyta have diverse and idiosyncratic reproductive systems, sometimes with complex reproductive organs. The unique habit among the algae of protecting the overwintering zygote within the tissues of the parent gametophyte is one of several characteristics Coleochaetales that suggest that they are a sister group to the embryophytes.[7]


Charophytes are frequently found in hard water with dissolved calcium or magnesium carbonates. They tolerate low concentrations of salt, and are found in the inner reaches of the Baltic Sea[8] and in tropical brackish lagoons[9] but not in marine environments. The water must be still, or only slow­-flowing, oligotrophic or mesotrophic and little pollution due to sewage.[citation needed]

Cell structure[edit]




Sexual reproduction[edit]


Vegetative propagation[edit]



  2. ^ Karol KG, McCourt RM, Cimino MT, Delwiche CF (December 2001). "The closest living relatives of land plants". Science 294 (5550): 2351–3. Bibcode:2001Sci...294.2351K. doi:10.1126/science.1065156. PMID 11743201. 
  3. ^ Vaughn, K.C.; Renzaglia, K.S. (2006). "Structural and immunocytochemical characterization of the Ginkgo biloba L. sperm motility apparatus.". Protoplasma 227 (2-4): 165–73. doi:10.1007/s00709-005-0141-3. 
  5. ^ Tree of Life: Green plants
  6. ^ Hemsley, A.R. (1989). "The ultrastructure of the spores of the Devonian plant Parka decipiens". Annals of Botany 64 (3): 359–367. 
  7. ^ Becker, B.; Marin, B. (2009). "Streptophyte algae and the origin of embryophytes". Annals of Botany 103 (7): 999–1004. doi:10.1093/aob/mcp044. PMC 2707909. PMID 19273476. 
  9. ^ Palma-Silva, C.; Albertoni, E.F.; Esteves, F.A. (2004). "Charophytes as nutrient and energy reservoir in a tropical coastal lagoon impacted by humans (RJ, Brazil).". Brazilian Journal of Biology 64: 479–487. doi:10.1590/s1519-69842004000300011.