Homoeothrix (ex & Flahault) Kirchner, 1898, nom. cons.
Holotype species: Calothrix juliana Bornet & Flahault ex Gomont
Currently accepted name for the type species: Homoeothrix juliana (Bornet & Flahault ex Gomont) Kirchner
Original publication and holotype designation: Kirchner, O. (1898). Schizophyceae. In: Die natürlichen Pflanzenfamilien...I. Teil, Abt. 1a. (Engler, A. & Prantl, K. Eds), pp. 45-92. Leipzig: Wilhelm Engelmann.
Taxonomic status: currently recognized as a distinct genus.
Most recent taxonomic treatment adopted: Komárek, J., Kastovsky, J., Mares, J. & Johansen, J.R. (2014). Taxonomic classification of cyanoprokaryotes (cyanobacterial genera) 2014, using a polyphasic approach. Preslia 86: 295-335.
Description: Filamentous; filaments solitary or in groups, heteropolar, attached with one end to the substrate (usually by a mucilaginous pad) and with free second end, erected or irregularly waved and creeping on the substrate, with simple, firm, thin sheath enveloping the trichome and open at the apex, colourless or coloured (yellow-brown, violet). Trichomes up to 15 um wide at the base, uniserial, simple, +/- straight or waved, from the widened base continually attenuated to the ends up to a thin cellular hair (subg. Homoeothrix), or thin and cylindrical along the greatest part of a trichome and at the end hair-like elongated (Subg. Tapinothrix; probably different genera); at crosswalls usually constricted, rarely unconstricted; rarely false branching with one lateral branch, after division at necridic cells or between two vegetative cells (7; different genera 7). Cells shorter than wide or more or less isodiametric, rarely longer than wide before cell division, cylindrical or barrel-shaped, usually pale blue-green, olive-green or greyish, rarely (in large species) blue-green, without aerotopes; hair cells usually vacuolized. Heterocytes and akinetes absent.
Information contributed by: J. Komárek. The most recent alteration to this page was made on 19 Oct 2015 by M.D. Guiry.
Comments: All species are known from submerged biotopes. The majority of species grow on stones (on the upper or bottom sides) or epiphytic in streams (particularly in mountain creeks), in tarns, less on different substrates in other stagnant waters. One species is marine, few live endogloeic within mucilage of other algae. Almost all species are known from geographically limited areas.
Numbers of names and species: There are 47 species names in the database at present, as well as 6 infraspecific names. Of the species names, 23 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.
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: 19 October 2015 by M.D. Guiry
Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=43615
Please cite this record as:
M.D. 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 23 January 2019.