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Charales
Charales is an order of pondweeds, freshwater algae in the division Charophyta. They are green Plantae|plants believed to be the closest relatives of the Embryophyta|green land plants. Linnaeus established the genus (''Chara'') in 1753.
Description
The Charales, have large, macroscopic, thalli growing up to 120cm long, they are branched, multicellular, and use chlorophyll to photosynthesize. They grow in fresh water. They may be called '''stoneworts''', because the plants can become encrusted in lime (calcium carbonate) after some time. The "stem" is actually a central stalk consisting of giant, multinucleated Cell (biology)|cells. They are unique in having a whorl of small branchlets at each node in the stipe (botany)|stipe, this gives them a superficial resemblance to the genus ''Equisetum''. In these whorls it is possible to see the phenomenon of cytoplasmic streaming. In fact the streaming in ''Chara'' is the fastest recorded of any cell. Cytoplasmic streaming is caused by the microfilaments found inside the cell, as proven by the use of cytochalasin B to stop streaming.
There are about 400 species world-wide, with 33 in Great Britain|Britain and Ireland according to Groves and Bullock-Webster),['''Groves, J. and Bullock-Webster, G.R.''' 1920. ''The British Charophyta. Vol.1, Nitelleae''. London, The Ray Society]['''Groves, J. and Bullock-Webster, G.R.''' 1924. ''The British Charophyta. Vol.2, Characeae.''. London, The Ray Society] however (Stewart and Church (1992) reduce this to 21.['''Stewart, N.F. and Church, J.M.''' 1992. ''Red Data Books of Britain and Ireland.'' The Joint Nature Conservation Committee, Peterborough. ISBN 1 873701 24 1]
Species
British Isles
Ref: Stewart & Church (1992).
- ''Chara baltica'' Bruz.
- ''Chara canescens'' Desv. & Lois.
- ''Chara connivens'' Salzm. ex A.Braun
- ''Chara curta'' Nolta wx Kütz. (=''C.aspera'' var. ''curta'')
- ''Chara denudata'' (A.Braun) R.D.Wood
- ''Chara fragifera'' Durieu
- ''Chara intermedia'' Braun (=''C. papillosa'' Kütz. and ''C. contraria'' x ''hispida'')
- ''Chara mucosa'' J.Groves & Bullock-Webster
- ''Chara rudis'' (A.Braun) Leonh.
- ''Chara tomentosa'' L.
- ''Lamprothamnium papulosum'' (Wallr.) J.Groves
- ''Nitella capillaris'' (Krocker) J.Groves & Bullock-Webster
- ''Nitella gracilis'' (Smith) Agardh
- ''Nitella hyalina'' (DC.)Agardh
- ''Nitella mucronata'' (A.Braun)Miquel
- ''Nitella spanioclema'' J.Groves & Bullock-Webster (''Nitella flexilis'' var. ''spanioclema'' (J.Groves & Bullock-Webster)
- ''Nitella tenuissima'' (Desv.) Kütz.
- ''Nitellopsis obtusa'' (Desv.) J.Groves
- ''Topella'' ''intricata'' (Trent. ex Roth) Leonh.
- ''Tolypella nidifica'' (O.F.Müll.) Leonh. (= ''Tolypella nidifica'' var. ''nidifica'')
- ''Tolypella prolifera'' (Ziz. ex A.Braun) Leonh.
Other regions
- Family ''Chaetosphaeridiaceae''[ITIS Standard Report Page: Chaetosphaeridiaceae]
- ''Chaetosphaeridium globosum'' (Nordst.) Klebahn, 1893
- ''Chaetosphaeridium ovalis'' G. M. Smith, 1916
- ''Chaetosphaeridium pringsheimii'' Klebahn, 1892
- ''Conochaete comosa'' Klebahn, 1893[Algaebase :: Species Detail]
- ''Diplochaete solitaria'' Collins, 1901
Distribution
Ireland
- '''Co. Antrim'''['''Morton, O.''' 1992 ''in'' Hackney, P. (Ed.) ''Stewart & Corry's Flora of the North-east of Ireland.'' Institute of Irish Studies and The Queen's University of Belfast ISBN0 85389 446 9 (HB)]
- ''C.aspera'' Deth. ex Willd. var. ''aspera''
- ''C. globularis'' Thuill. var. ''globularis''
- ''C. vulgaris'' var. ''papillata'' Wallr. ex A. Braun
- ''C. globularis'' var. ''virgata'' (Kützing) R.D.Wood
- ''C. vulgaris'' L. var. ''vulgaris''
- ''C. vulgaris'' L. var. ''contraria'' (A.Braun ex Kützing) J.A. Moore
- ''C. vulgaris'' var. ''longibracteata'' (Kützing) J. Groves & Bullock-Webster
- ''C. vulgaris'' var. ''papillata'' Wallr. ex A. Braun
- ''Nitella flexilis'' (L.) var. ''flexilis''
- ''Nitella translucens'' (Pers.) C.A. Ag.
- '' Tolypella nidifica'' (O. Mill.) Leonh. var. ''glomerata'' (Desv.) R.D.Wood
- '''Co. Down'''
- ''C. aspera'' Deth. ex Willd. var. ''aspera''
- ''C. aspera'' var. ''curta'' (Nolte ex Kützing) Braun ex Leonh.
- ''C. globularis'' Thuill. var. ''globularis''
- ''C. vulgaris'' var. ''papillata'' Wallr. ex A. Braun
- ''C. globularis'' var. ''virgata'' (Kützing) R.D.Wood
- ''C. globularis'' var. ''annulata'' (Lilleblad) J.A.Moore
- ''C. hispida'' L.
- ''C. hispida'' var. ''hispida''
- ''C. hispida'' var. ''major'' (Hartm.) R.D. Wood
- ''C. hispida'' var. ''rudis'' A. Braun
- ''C. pedunculata'' Kützing
- ''C. vulgaris'' L. var. ''vulgaris''
- ''C. vulgaris'' L. var. ''contraria'' (A.Braun ex Kützing) J.A. Moore
- ''C. vulgaris'' var. ''longibracteata'' (Kützing) J. Groves & Bullock-Webster
- ''C. vulgaris'' var. ''papillata'' Wallr. ex A. Braun
- ''Nitella flexilis'' (L.) var. ''flexilis''
- ''Nitella translucens'' (Pers) C.A. Ag.
- '' Tolypella nidifica'' (O. Mill.) Leonh. var. ''glomerata'' (Desv.) R.D.Wood
- '''Co. Londonderry'''
- ''C.aspera'' Deth. ex Willd. var. ''aspera''
- ''C. vulgaris'' var. ''papillata'' Wallr. ex A. Braun
- ''C. globularis'' Thuill. var. ''globularis''
- ''C. globularis'' var. ''virgata'' (Kützing) R.D.Wood
- ''C. hispida'' L.
- ''C. hispida'' var. ''hispida''
- ''C. vulgaris'' L. var. ''vulgaris''
- ''C. vulgaris'' L. var. ''contraria'' (A.Braun ex Kützing) J.A. Moore
- ''C. vulgaris'' var. ''papillata'' Wallr. ex A. Braun
- ''Nitella flexilis'' (L.) var. ''flexilis''
- ''Nitella translucens'' (Pers) C.A. Ag.
- '' Tolypella nidifica'' (O. Mill.) Leonh. var. ''glomerata'' (Desv.) R.D.Wood
- '''Co. Mayo'''.Recent records have been published from Clare Island.['''Guiry, M.D., John, D.M., Rindi, F. and McCarthy, T.K''' 2007. ''New Survey of Clare Island Volume:6: The Freshwater and Terrestial Algae.'' Royal Irish Academy. ISBN 13:978-1-904890-3-7]
- ''C. virgata'' Kützing
- ''N. flexilis'' (Linnaeus) C.Agardh
- ''N. translucens'' (Persoon) C.Agardh
Ecology
The Characeae because of the are aquatic though some can survive in brackish or maritime habitats. They are to be found usually in still, clear, non-flowing, water attached by rhizoids. They can be pioneer colonizers or ephemerals. ['''John, D.M., Whitton, B.A. and Brook, A.J.''' 2002. ''The Freshwater Algal Flora of the British Isles.'' Cambridge University Press, London. ISBN 0 521 77051 3] They are usually found in low to medium nutrient-rich water and tend to disappear due to eutrophication.
Life history
The antheridia and oogonia are protected by a layer of sterile cell (biology)|cells when mature; the oogonium is oblong in shape and consists of a single egg, while the spherical antheridium is packed with threadlike cells that produce spermatia. As a result, the '''Charales''' have the most complex structure of all green algae, if indeed they should be so labelled.
The possible ancestors of the Embryophyta|land plants are also known as '''brittleworts''' or '''skunkweed.''' These curious labels arise from the fragility of their lime-encrusted stems, and from the foul odor these produce when stepped on.
Many Botany|botanists propose that the stoneworts and their relatives be placed in a phylum, division, sub-kingdom, or even kingdom by themselves, often named '''Charophyta'''. Their biological classification|classification by taxonomy|taxonomists is currently undergoing much cladistics|cladistic scrutiny. Further DNA and RNA analysis may prove the '''charophytes''' to be a crucial evolutionary missing link|link in the phylogenetic tree of life, the critical developmental step from the algae toward the bryophyte|non-vascular and then vascular plant|vascular land plants.
References
Further reading
- Bryant, J. The stoneworts (Chlorophyta, Charales). In Guiry, M.D., John, D.M., Rindi, F. and McCarthy, T.K. 2007. ''New Survey of Clare Island.'' Royal Irish Academy. ISBN-13:978--904890-31-7.
- Lloyd, James. 2007. "Cytoskeletal Structures Responsible for Cytoplasmic Streaming in Chara." St. Vincent-St. Mary High School in Accordance with Dr. Donald Ott of The University of Akron. (Science Inquiry)
- Morton, O. 1992. ''Charophyta.'' pp.91 - 94 ''in'' Hackney, P. (Ed) 1992 ''Stewart and Corry's Flora of the North-east of Ireland. Third edition. '' Institute of Irish Studies. The Queen's University of Belfast.
- Schaible, R. and Schubert, H. 2008. The ccurrence of sexual ''Chara canesces'' populations (Charophyceae) is not related to ecophysiological potentials with respect to salinity and irradiance. ''Eur. J. Phycol.'' '''43''': 309 - 316.
Further links
- Images of Charales
- University California
- ''Chara curta'' in Ireland
Category:Green algae
Category:Plant taxonomy
Category:Plant orders
Related Images- Submerse meadow of ''Chara spec.''
- Limy crust on ''Chara'' spec. in a spring pond
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