Griffithsia C.Agardh, 1817: 28

Classification:
Empire Eukaryota
Kingdom Plantae
Phylum Rhodophyta
Subphylum Eurhodophytina
Class Florideophyceae
Subclass Rhodymeniophycidae
Order Ceramiales
Family Wrangeliaceae
Tribe Griffithsieae

Holotype species: Griffithsia corallina C.Agardh

Currently accepted name for the type species: Griffithsia corallinoides (Linnaeus) Trevisan

Original publication and holotype designation:Agardh, C.A. (1817). Synopsis algarum Scandinaviae, adjecta dispositione universali algarum. pp. [i]-xl, [1]-135. Lundae [Lund]: Ex officina Berlingiana.
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Taxonomic status: currently recognized as a distinct genus.

Description: Thallus to 15(-30) cm, axes subdichotomously or laterally branched, ecorticate or rhizoidally corticated below. Cells large, multinucleate. Whorls of polychotomous trichoblasts often associated with reproductive structures. Female axis lateral, 3-celled, subapical cell bearing an abaxial pericentral cell and 1(-2) adaxial supporting cells, each with sterile apical cell and 1(-2) 4-celled carpogonial branches. Fusion of carpogonium either directly with supporting cell by means of connecting cell or with auxiliary cell cut off from supporting cell without involvement of connecting cell.Carposporophyte with globose carposporangia and involucre of 2-celled filaments borne on hypogenous cell with large outer cells curved around carposporophyte. Fusion cell large. Spermatangia and tetrasporangia on whorls of polychotomous fascicles clustered in constrictions between axial cells. Easily recognized by large globular to cylindrical multinucleate axial cells.

Comments: Widespread on rocks or epiphytic in sublittoral to eulittoral zone and in rock-pools. Recent redefinition of the genus by Baldock (1976) excludes several species previously assigned to Griffithsia and leads to 4 subgeneric groups based largely on tetrasporangial and spermatangial features.

Numbers of names and species: There are 99 species (and infraspecific) names in the database at present, of which 38 have been flagged as currently accepted taxonomically.

Names: ('C' indicates a name that is currently 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):

References
Choi, H.-G., Kraft, G.T., Kim, H.-S., Guiry, M.D. & Saunders, G.W. (2008). Phylogenetic relationships among lineages of the Ceramiaceae (Ceramiales, Rhodophyta) based on nuclear small subunit rDNA sequence data. Journal of Phycology 44: 1033-1048.

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: http://www.algaebase.org/search/genus/detail/?genus_id=32770

Citing AlgaeBase
Cite this record as:
Guiry, M.D. & Guiry, G.M. 2013. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 22 May 2013.

Algaebase taxon LSID: urn:lsid:algaebase.org:taxname:8802