156,368 species and infraspecific names are in the database, 22,021 images, 60,434 bibliographic items, 446,051 distributional records.

Sphacelaria Lyngbye, 1818

Classification:
Empire Eukaryota
Kingdom Chromista
Phylum Ochrophyta
Class Phaeophyceae
Subclass Dictyotophycidae
Order Sphacelariales
Family Sphacelariaceae

Holotype species: Sphacelaria reticulata Lyngbye

Original publication and holotype designation: Hornemann, J.V. (1818). [Flora danica] 9, fasc. 27. . Havniae [Copenhagen].
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Taxonomic status: currently recognized as a distinct genus.

Most recent taxonomic treatment adopted: Silberfeld, T., Rousseau, F. & Reviers, B. de (2014). An updated classification of brown algae (Ochrophyta, Phaeophyceae). Cryptogamie Algologie 35(2): 117-156.

Nomenclatural notes
Draisma & Prud'homme van Reine (Taxon. 2010: 1891, 1892) propose to conserve the name Sphacelaria with a conserved type (S. cirrosa (Roth) C. Agardh 1824). - (18 Jan 2011) - Wendy Guiry

Taxonomic notes
Consists only of the former subgenus Propagulifera; prop. cons. type of genus: Sphacelaria cirrosa (Draisma et al. 2010: fig. 3). - (2 Nov 2010) - Wendy Guiry

Description: Rather small (about 2-10 cm tall), usually marine, brownish to olivaceous plants, forming subglobose, hemispherical, penicillate, or complanate tufts or spreading mats; occasionally crustaceous, usually heterotrichous. Basal parts consisting of monostromatic or polystromatic discs, or of stolons and rhizoids ramifying on or penetrating into the support; rarely lacking. Terete, articulate, isodiametric, erect filaments subsimple to bushy, quite rigid to flaccid, bearing sparse to many, determinate or indeterminate, branched or unbranched, usually hemiblastic, distichous, helicoid or irregularly placed laterals. Segments cut off from the usually conspicuous cylindrical apical cell each transversely divided once preceeding longitudinal segmentation. Secondary transverse divisions in secondary segments frequent, infrequent or absent. Rhizoids on erect filaments divaricate, corticating, or absent. Hairs present or absent, often in axils of laterals. Pericysts present or absent. Many small discoid parietal chloroplasts without pyrenoids in each cell. Reproductive structures: special vegetative branchlets (propagules), plurilocular gametangia , neutral plurilocular zoidangia and unilocular zoidangia. Cosmopolitan marine in intertidal zone and in sublittoral.

Two species are known to occur in fresh water in the USA and China. Most species occur in temperate areas, some in arctic or antarctic areas or in the tropics. The diplohaplontic life history is isomorphic or slightly heteromorphic with isogamy or anisogamy. In some species there are male and female plants, while other species are probably monoecious. Occurrence of neutral plurilocular zoidangia is probable in several species. Parthenogenesis has been observed and vegetative propagation by propagules occurs in several species.

Information contributed by: W.F. Prud'homme van Reine. The most recent alteration to this page was made on 30 Jul 2015 by M.D. Guiry.

Comments: Both temperature and daylength have a distinct influence on the life history of Sphacelaria spp., see van den Hoek and Flinterman (1968) and Colijn & van den Hoek (1971); vegetative propagation occurs usually mainly in the warm season, while plurilocular and unilocular reproductive organs are more frequent in the colder seasons. Unattached forms occur in brackish seas (esp. the Baltic) and in seagrass meadows in temperate seas. These free-living forms usually propagate only by fragmentation. Basic chromosome number 8-12 according to Cole (1967).

Numbers of names and species: There are 126 species names in the database at present, as well as 50 infraspecific names. Of the species names, 39 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
Wehr, J.D. (2003). Brown Algae. In: Freshwater Algae of North America, Ecology and Classification. (Wehr, J.D. & Sheath, R.G. Eds), pp. 757-774. San Diego: Academic Press.

Draisma, S.G.A., Prud'homme van Reine, W.F. & Kawai, H. (2010). A revised classification of the Sphacelariales (Phaeophyceae) inferred from a psbC and rbcL based phylogeny. European Journal of Phycology 45(3): 308-326.

Draisma, S.G.A., Prud'homme van Reine, W.F. & Kawai, H. (2010). A revised classification of the Sphacelariales (Phaeophyceae) inferred from a psbC and rbcL based phylogeny. European Journal of Phycology 45(3): 308-326.

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: 29 December 2000 by M.D. Guiry

Verified by: 30 July 2015 by M.D. Guiry

Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=32919

Citing AlgaeBase
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 September 2019.

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