153,871 species and infraspecific names are in the database, 21,012 images, 59,576 bibliographic items, 413,474 distributional records.

Microthamnion Nägeli, 1849

Classification:
Empire Eukaryota
Kingdom Plantae
Subkingdom Viridiplantae
Infrakingdom Chlorophyta infrakingdom
Phylum Chlorophyta
Subphylum Chlorophytina
Class Trebouxiophyceae
Order Microthamniales
Family Microthamniaceae

Holotype species: Microthamnion kuetzingianum Nägeli ex Kützing

Original publication and holotype designation: Kützing, F.T. (1849). Species algarum. pp. [i]-vi, [1]-922. Lipsiae [Leipzig]: F.A. Brockhaus.
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Taxonomic status: currently recognized as a distinct genus.

Most recent taxonomic treatment adopted: Tsarenko, P.M. (2011). Trebouxiophyceae. In: Algae of Ukraine: diversity, nomenclature, taxonomy, ecology and geography. Volume 3: Chlorophyta. (Tsarenko, P.M., Wasser, S.P. & Nevo, E. Eds), pp. 61-108. Ruggell: A.R.A. Gantner Verlag K.-G..

Taxonomic notes
Darienko et al. (2010: fig. 1) place Microthamnion kuetzingianum and Fusochloris perforata in the Microthamnion-clade (Trebouxiophyceae). Neustupa et al. (2011: fig. 22) include M. kuetzingianum and Coleochlamys perforata in the Microthamniales. - (16 Mar 2011) - Wendy Guiry

Description: Plants consisting of an erect system of uniseriate filaments, terminating in obtuse cells. Branches each arise towards distal end of cell, often cross wall of laterals remote from point of origin. Cells uninucleate, with parietal chloroplast and no pyrenoid. Asexual reproduction by biflagellate zoospores, these rounded posteriorly with distal flagellated end projecting outwards into a neck. 2 to 32 zoospores per sporangium, dehiscing by rupture of zoosporangium wall. Reports of sexual reproduction and production of akinetes and aplanospores require confirmation. Microthamnion most common in still or flowing, unpolluted freshwater. The great degree of morphological plasticity exhibited by the genus has given rise to taxonomic problems. It seems that many of the infraspecific taxa attributed to Microthamnion are trivial growth forms whose recognition were based on minor differences in what are now known to be unreliable vegetative features. Very widely distributed. Zoospore ultrastructure of Microthamnion shares many features with such genera as Pleurastrum, Tetraselmis, and Friedaea. Besides the Chaetophorales it has been assigned to Pleurastrales, Ctenocladales, and the Microthamniales. Its taxonomic position remains uncertain.

Information contributed by: D.M. John. The most recent alteration to this page was made on 24 Feb 2014 by M.D. Guiry.

Numbers of names and species: There are 8 species names in the database at present, as well as 2 infraspecific names. Of the species names, 5 have been flagged as accepted taxonomically on the basis of the listed literature under the species name. In some instances, opinions on taxonomic validity differ from author to author and users are encouraged to form their own opinion. AlgaeBase is a work in progress and should not be regarded as a definitive source only as a guide to the literature..

Names: ('C' indicates a name that is accepted taxonomically; 'S' a homotypic or heterotypic synonym; 'U' indicates a name of uncertain taxonomic status, but which has been subjected to some verification nomenclaturally; 'P' indicates a preliminary AlgaeBase entry that has not been subjected to any kind of verification. For more information on a species click on it to activate a link to the Species database):

Click here to also show infraspecific names in the list below.

References
Neustupa, J., Eliás, M., Skaloud, P., Nemcová, Y. & Sejnohová, L. (2011). Xylochloris irregularis gen. et sp. nov. (Trebouxiophyceae, Chlorophyta), a novel subaerial coccoid green alga. Phycologia 50(1): 57-66.

Friedl, T. & O'Kelly, C.J. (2002). Phylogenetic relationships of green algae assigned to the genus Planophila (Chlorophyta): evidence from 18S rDNA sequence data and ultrastructure. European Journal of Phycology 37: 373-384.

Darienko, T., Gustavs, L., Mudimu, O., Menendez, C.R., Schumann, R., Karsten, U., Friedl, T. Proschold, T. (2010). Chloroidium, a common terrestrial coccoid green alga previously assigned to Chlorella (Trebouxiophyceae, Chlorophyta). European Journal of Phycology 45(1): 79-95.

Sluiman, H.J., Guihal, C. & Mudimu, O. (2008). Assessing phylogenetic affinities and species delimitations in Klebsormidiales (Streptophyta): nuclear-encoded rDNA phylogenies and ITS secondary structure models in Klebsormidium, Hormidiella, and Entransia. Journal of Phycology 44(1): 183-195.

Verification of data
Users are responsible for verifying the accuracy of information before use, as noted on the website Content page.

Contributors
Some of the descriptions included in AlgaeBase were originally from the unpublished Encyclopedia of Algal Genera, organised in the 1990s by Dr Bruce Parker on behalf of the Phycological Society of America (PSA) and intended to be published in CD format. These AlgaeBase descriptions are now being continually updated, and each current contributor is identified above. The PSA and AlgaeBase warmly acknowledge the generosity of all past and present contributors and particularly the work of Dr Parker.

Descriptions of chrysophyte genera were subsequently published in J. Kristiansen & H.R. Preisig (eds.). 2001. Encyclopedia of Chrysophyte Genera. Bibliotheca Phycologica 110: 1-260.

Created: 28 December 2000 by M.D. Guiry

Verified by: 24 February 2014 by M.D. Guiry

Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=42758

Citing AlgaeBase
Please cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2018. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 14 December 2018.

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