From Wikipedia, the free encyclopedia
Charales is an order of pondweeds, freshwater
algae in the division Charophyta. They are
green plants believed to be the closest relatives
of the green land plants. Linnaeus established the
genus (Chara) in 1753.
Description
The Charales, have large, macroscopic, thalli growing up to
120 cm long, they are branched, multicellular, and
use chlorophyll to
photosynthesize. They grow in fresh water. They may
be called stoneworts,[1]
because the plants can become encrusted in lime (calcium
carbonate) after some time. The "stem" is actually a central
stalk consisting of giant, multinucleated cells. They are unique in having a whorl
of small branchlets at each node in the 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 worldwide, with 33 in Britain and Ireland according to Groves and
Bullock-Webster),[2
][3
] however (Stewart and Church (1992) reduce this
to 21.[4]
Species
Submerse meadow of
Chara spec.
Limy crust on
Chara spec. in a spring pond
British
Isles
Ref: Stewart & Church (1992).[4]
- 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[5]
- Chaetosphaeridium
globosum (Nordst.) Klebahn, 1893
- Chaetosphaeridium ovalis G. M. Smith, 1916
- Chaetosphaeridium pringsheimii Klebahn, 1892
- Conochaete comosa Klebahn, 1893[6]
- Diplochaete solitaria Collins, 1901
Distribution
Ireland
- Co. Antrim[7]
- 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[7]
- 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[7]
- 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.[8]
- C. virgata Kützing
- N. flexilis (Linnaeus) C.Agardh
- N. translucens (Persoon) C.Agardh
Ecology
The Characeae 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.[9
] 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 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 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 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 classification by taxonomists is currently
undergoing much cladistic scrutiny. Further DNA and RNA analysis
may prove the charophytes to be a crucial evolutionary link in the phylogenetic
tree of life, the critical developmental step from the algae toward the non-vascular and then vascular land
plants.
References
- ^ Kapraun DF (April 2007). "Nuclear DNA content
estimates in green algal lineages: chlorophyta and
streptophyta". Ann. Bot. 99 (4):
677–701. doi:10.1093/aob/mcl294.
PMID 17272304. http://aob.oxfordjournals.org/cgi/pmidlookup?view=long&pmid=17272304.
- ^
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
- ^ a
b
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
- ^
ITIS Standard Report Page:
Chaetosphaeridiaceae
- ^
Algaebase :: Species
Detail
- ^ a
b
c
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
ISBN 0 85389 446 9 (HB)
- ^ 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 978-1-904890-3-7
- ^
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
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
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.
- Desai, Udaysingh and Karande C.T. 2008. "Biodiversity of
Charophytes from Kolhapur District, Maharashtra". Shivaji
University, Kolhapur.
Further
links