Phacus Dujardin, 1841, nom. et typ. cons.
Holotype species: Phacus longicauda (Ehrenberg) Dujardin
Original publication and holotype designation: Dujardin, F. (1841). Histoire naturelle des Zoophytes, Infusoires, comprenant la physiologie et la clasification de ces animaux et la manière de les étudier à l'aide du microscope. pp. i-xii, 1-684. Paris: Librarie Encyclopédique de Roret.
Taxonomic status: currently recognized as a distinct genus.
Gender: This genus name is currently treated as masculine.
Most recent taxonomic treatment adopted: Kostygov, A.Y., Karnkowska, A., Votýpka, J., Tashyreva, D., Maciszewski, K, Yurchenko, V. & Lukeš J. (2021). Euglenozoa: taxonomy, diversity and ecology, symbioses and viruses. Open Biology 11(200407): 1-47.
Presumably from Phakos, lentil or lens, masculine (see Brown 1956: 470). According to Art. 62.1, "a generic name retains the gender assigned by nomenclatural tradition, irrespective of classical usage or the author's original usage. A generic name without a nomenclatural tradition retains the gender assigned by its author (but see Art. 62.4). Note 1. Tradition for generic names usually maintains the classical gender of the corresponding Greek or Latin word, if such exists, but may differ." - (22 Sep 2016) - M.D. Guiry
Description: Green flagellates with rigid, compressed cells, most species being very flat and leaf-shaped, often with ridges, folds or grooves running helically or longitudinally, giving the cells irregular or triradiate cross-sections; (20)35(50+) _ (10)25(40+) _m; many species with a long posterior spine, shaped like flattened spinning tops; some species twisted into flat corkscrews. Flagella, eyespot and flagellar swelling as in Euglena. Chloroplasts usually small, discoid and numerous, usually without pyrenoids; a few species (e.g. P. splendens) have large flat chloroplasts with pyrenoids; paramylon typically deposited as a few large granules (often rings) together with many small ones. Pochmann (1942) reviewed the genus and proposed the subgenus Phacus for green forms and Hyalophacus for colorless forms; the latter are treated here as a separate genus; Pochmann and, previously, Lemmermann (1901) divide the green genera into several sections (see Huber-Pestalozzi, 1955, and Bourrelly, 1970). EM studies include those by Dynesius and Walne (1975), Bourrelly and Couté (1981). Freshwater; worldwide. Emend. Marin & Melkonian (in Marin et al. 2003: 101). Emend. Linton & Karnkowska 2010 in Linton et al. 2010: 609.
Information contributed by: G.F. Leedale. The most recent alteration to this page was made on 18 Mar 2021 by M.D. Guiry.
Numbers of names and species: There are 297 species names in the database at present, as well as 273 infraspecific names. Of the species names, 158 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.
Leander, B.S. & Farmer, M.A. (2001). Evolution of Phacus (Euglenophyceae) as inferred from pellicle morphology and SSU rDNA. Journal of Phycology 37: 143-159.
Nudelman, M.A., Rossi, M.S., Conforti, V. & Triemer, R.E. (2003). Phylogeny of Euglenophyceae based on small subunit rDNA sequences: taxonomic implications. Journal of Phycology 39: 226-235.
Kim, J.I., Shin, W. & Triemer, R.E. (2010). Multigene analyses of photosynthetic euglenoids and new family, Phacaceae (Euglenales). Journal of Phycology 46(6): 1278-1287.
Lukomska-Kowalczyk, M., Fells, A., Chaber, K., Milanowski, R. & Zakrys, B. (2020). Taxon-rich phylogeny and taxonomy of the genus Phacus (Euglenida) based on morphological and molecular data. Journal of Phycology 56(5): 1135-1156.
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: 18 March 2021 by M.D. Guiry
Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=43655
Please cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2021. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 11 April 2021.