Melanothamnus& , 1901
Holotype species: Melanothamnus somalensis Bornet & Falkenberg
Original publication and holotype designation: Falkenberg, P. (1901). Die Rhodomelaceen des Golfes von Neapel und der angrenzenden Meeres-Abschnitte. Fauna und Flora des Golfes von Neapel, Monographie 26. pp. i-xvi, 1-754, 10 figs, 24 pls. Berlin.
Taxonomic status: currently recognized as a distinct genus.
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.
Huisman (2018: 538) notes: "The recent study by Díaz-Tapia et al. (2017) sought to clarify the relationships in the Neosiphonia/Polysiphonia complex using a combination of molecular and morphological analyses. Their study demonstrated that the type species of Neosiphonia, N. flavimarina, resolved in a clade with the type species of the earlier described Melanothamnus, and they transferred all species of Neosiphonia to that genus. Their taxonomic scheme is followed here. Three further species are transferred to Melanothamnus here, due primarily to their similarity with species previously regarded as belonging to Neosiphonia. These species (M. delicatulus, M. infestans and M. quadratus) do not display what Díaz-Tapia et al. (2017) regarded as a diagnostic feature of Melanothamnus, the presence of plastids restricted to radial walls of cells. However, some of the species included by those authors (M. nudus and M. tongatensis) also do not appear to conform to this distinction and, until further work, the taxonomy presented here should be regarded as tentative." - (9 Oct 2018) - M.D. Guiry
Description: Thallus solitary, epiphytic or epilithic, polysiphonous, erect or decumbent; holdfasts of tightly clumped rhizoids cut off from basal pericentral or cortical cells; pericentral cells 4–9, corticate or not; branches mostly exogenous, some lateral branches cicatrigenous, not arising in connection with a trichoblast; trichoblasts moderately developed on the apex of branchlets, 1 per segment or with naked segments, spirally arranged, slender, elongate, simple or forked, with uninucleate cells, deciduous, often leaving conspicuous scar cells. Spermatangial branches arising from 1 fork of the trichoblast, cylindrical, sometimes with a sterile tip; procarps with a 3-celled carpogonial branch; cystocarps scattered on branchlets, not aggregated, globose or ovoid, very shortly pedicellate. Tetrasporangia tetrahedrally divided, forming spiral series in upper branchlets [after Díaz-Tapia et al. (2017: tab. 1)].
Information contributed by: Huisman (2018). The most recent alteration to this page was made on 17 May 2019 by M.D. Guiry.
Numbers of names and species: There are 54 species names in the database at present, as well as 1 infraspecific names. Of the species names, 54 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.
Díaz-Tapia, P., McIvor, L., Freshwater, D.W., Verbruggen, H., Wynne, M.J. & Maggs, C.A. (2017). The genera Melanothamnus Bornet & Falkenberg and Vertebrata S.F. Gray constitute well-defined clades of the red algal tribe Polysiphonieae (Rhodomelaceae, Ceramiales). European Journal of Phycology 52(1): 1-20, 77 figs.
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: 28 December 2000 by M.D. Guiry
Verified by: 17 May 2019 by M.D. Guiry
Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=42625
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 24 June 2019.