Microthamnion Nägeli, 1849

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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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 2014-02-24 by M.D. Guiry.

Taxonomic status: This name is of an entity that is currently accepted taxonomically.

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..

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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Some of the descriptions included in AlgaeBase were originally from the unpublished Encyclopedia of Algal Genera, organised in the 1990s by Dr Bruce Parker on behalf of the Phycological Society of America (PSA) and intended to be published in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.

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

Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 24 February 2014. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 22 November 2024