Lectotype species: Hydrianum ovale Rabenhorst
Original publication:Rabenhorst, L. (1868). Flora europaea algarum aquae dulcis et submarinae. Sectio III. Algae chlorophyllophyceas, melanophyceas et rhodophyceas complectens. pp. i-xx, 1-461, 51 figs. Lipsiae [Leipzig]: Apud Eduardum Kummerum.
Type designated in Fott, B. (1975). Übersicht der Familie der Characiaceae (Chlorococcales) mit taxonomischen Namensänderungen und Neubeschreibungen. Preslia 47: 211-231.
Taxonomic status: currently recognized as a distinct genus.
Most recent taxonomic treatment adopted: Tsarenko, P.M. (2011). Chlorococcales. In: Algae of Ukraine: diversity, nomenclature, taxonomy, ecology and geography. Volume 3: Chlorophyta. (Tsarenko, P.M., Wasser, S.P. & Nevo, E. Eds), pp. 232-264. Ruggell: A.R.A. Gantner Verlag K.-G..
Description: Solitary or clustered cells attached by mucilaginous basal pad or short to prominent stipe to ca 10 µm long. Cells 12-45 x 6-15.5 µm, cylindrical to oval or spindle shaped, with rounded ends, usually straight, but some species distinctly curved. Cell walls smooth. Cells uninucleate; chloroplast parietal, single when young, often multiple with maturity; pyrenoids mostly absent but some species with one (e.g., H. coronatum) or two or more (H. pyrenoidiferum) per chloroplast. Asexual reproduction by biflagellate zoospores; spores released through apical pore or subapical tear in sporangial wall. After spore development, one spore (or portion of cytoplasm from vegetative cell) remains in sporangium and develops into new vegetative cell. After motile period spores attach at anterior end. Zoospores with single chloroplast, at least in some species with pyrenoid and stigma. Sexual reproduction unknown. Hydrianum in freshwater marshes, moors and bogs, often epiphytic on various algae or macrophytes; most species reported from northern and eastern Europe with record from Africa. Hydrianum may be confused with Characiopsis (Tribophyceae) which has similar morphology. Genus similar to Characium but differs in details of sporulation and by presence of lateral tear for spore release in Characium. Species taxonomy based on details of cell size and shape, chloroplast form and stipe morphology. Only half the species well described.
Information contributed by: D. Gargary & T. Kalina. The most recent alteration to this page was made on 2 May 2017 by M.D. Guiry.
Numbers of names and species: There are 17 species names in the database at present, as well as 1 infraspecific names. Of the species names, 11 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.
Cambra Sánchez, J., Álvarez Cobelas, M. & Aboal Sanjurjo, M. (1998). Lista florística y bibliográfica de los clorófitos (Chlorophyta) de la Península Ibérica, Islas Baleares e Islas Canarias. pp. 1-614. Burgos: Asociación Española de Limnología.
Verification of data
Users are responsible for verifying the accuracy of information before use, as noted on the website Content page.
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: 11 April 2002 by M.D. Guiry
Verified by: 02 July 2012 by Michael Guiry
Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=43383
Please cite this record as:
Michael Guiry in Guiry, M.D. & Guiry, G.M. 2019. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 20 May 2019.