Digenea C., 1822
Holotype species: Digenea simplex (Wulfen) C.Agardh
Original publication and holotype designation: Agardh, C.A. (1822). Species algarum rite cognitae, cum synonymis, differentiis specificis et descriptionibus succinctis. Volumen primum pars posterior. pp. [v-vi], 169-398. Lundae [Lund]: ex officina Berlingiana.
Taxonomic status: currently recognized as a distinct genus.
Gender: This genus name is currently treated as feminine.
Most recent taxonomic treatment adopted: Díaz-Tapia, P., Maggs, C.A., West, J.A. & Verbruggen, H. (2017). Analysis of chloroplast genomes and a supermatrix inform reclassification of the Rhodomelaceae (Rhodophyta). Journal of Phycology 53(5): 920-937, 2 figs.
Monotypic when first introduced. - (26 Jan 2017) - M.D. Guiry
Description: Thallus erect, bushy, cartilaginous, dichotomously or irregularly branched. Primary axes bearing short closely-set simple determinate branches, these with deciduous trichoblasts near the tips. Structure uniaxial, with each axial cell bearing 9 or 10 pericentral cells (not always obvious), surrounded by a pseudoparenchymatous medulla and a thin cortex. Structure of determinate branches with 6–9 pericentral cells and a thin pseudoparenchymatous cortex. Spermatangia in oval discs clustered at the tips of fertile branches, replacing trichoblasts, with a sterile margin. Cystocarps ovoid, terminal and lateral on the determinate branches. Tetrasporangia tetrahedrally divided, in the distal region of lateral determinate branches, 1 per segment.
Information contributed by: Huisman (2018). The most recent alteration to this page was made on 9 Oct 2018 by M.D. Guiry.
Comments: Intertidal to subtidal, tropical to subtropical regions in most parts of the world.
Numbers of names and species: There are 11 species names in the database at present, as well as 1 infraspecific names. Of the species names, 6 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: 29 December 2000 by M.D. Guiry
Verified by: 18 July 2017 by M.D. Guiry
Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=33998
Please cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2020. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 26 February 2020.