Callithamnion Lyngbye, 1819
Lectotype species: Callithamnion corymbosum (Smith) Lyngbye
Original publication: Lyngbye, H.C. (1819). Tentamen hydrophytologiae danicae continens omnia hydrophyta cryptogama Daniae, Holsatiae, Faeroae, Islandiae, Groenlandiae hucusque cognita, systematice disposita, descripta et iconibus illustrata, adjectis simul speciebus norvegicis. pp. [i]-xxxii, -248, 70 pls. Hafniae [Copenhagen]: typis Schultzianis, in commissis Librariae Gyldendaliae.
Type designated in: Kylin, H. (1956). Die Gattungen der Rhodophyceen. pp. i-xv, 1-673, 458 figs. Lund: C.W.K. Gleerups.
Description: Thallus erect to l0 cm high, axes monosiphonous, irregularly branched, with or without rhizoidal cortication, and bearing alternately-placed, branched or unbranched determinate branchlets singly from each cell of the mature axis. Cells multinucleate. Chromosomes 0.3-1.5& long; haploid number 28-33 in most species. Procarps and carposporophytes at intervals of several cells near branch apices. Carpogonial branch 4-celled borne on first formed of pair of opposite pericentral cells with carpogonium lying between 2 auxiliary cells cut off respectively from pericentral cells. Fusion between carpogonium and auxiliary cells by means of connecting cells. Carposporophytes bearing successive groups of carposporangia. Spermatangial clusters and tetrahedrally-divided tetrasporangia borne on cells of determinate branchlets. Common and widespread in most habitats. In culture presence of terminal hairs and density of axial cortication appear to increase in rougher water conditions. Sporangial types (mono-, bi-, poly-) inconsistent lacking taxonomic significance. Range of plant form causing confusion in species delimitation.
Information contributed by: E.M. Wollaston. The most recent alteration to this page was made on 2021-11-24 by M.D. Guiry.
Taxonomic status: This name is of an entity that is currently accepted taxonomically.
Gender: This genus name is currently treated as neuter.
Most recent taxonomic treatment adopted: Schneider, C.W. & Wynne, M.J. (2007). A synoptic review of the classification of red algal genera a half a century after Kylin's "Die Gattungen der Rhodophyceen". Botanica Marina 50: 197-249.
Comments: Concept of genus Callithamnion has undergone 2 major changes (a) Nägeli (1861) transferred species without alternate branchlets to Antithamnion, Rhodochorton and Acrochaetium, (b) Feldmann-Mazoyer (1941) erected Aglaothamnion for species having uninucleate cells, zig-zag carpogonial branches and lobed groups of carposporangia, and recircumscribed Callithamnion. Aglaothamnion now sometimes regarded as synonym of Callithamnion with insufficient evidence for separate evolutionary lines of development.
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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: https://www.algaebase.org/search/genus/detail/?genus_id=126
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 24 November 2021. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 02 October 2022