156,801 species and infraspecific names are in the database, 22,033 images, 60,602 bibliographic items, 450,083 distributional records.

Acrothamnion J.Agardh, 1892

Classification:
Empire Eukaryota
Kingdom Plantae
Subkingdom Biliphyta
Phylum Rhodophyta
Subphylum Eurhodophytina
Class Florideophyceae
Subclass Rhodymeniophycidae
Order Ceramiales
Family Ceramiaceae
Subfamily Ceramioideae
Tribe Antithamnieae

Holotype species: Acrothamnion pulchellum J.Agardh

Currently accepted name for the type species: Acrothamnion preissii (Sonder) E.M.Wollaston

Original publication and holotype designation: Agardh, J.G. (1892). Analecta algologica. Acta Universitatis Lundensis 28(6): 1-182, 3 pls.
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Taxonomic status: currently recognized as a distinct genus.

Most recent taxonomic treatment adopted: Athanasiadis, A. (1996). Morphology and classification of the Ceramioideae (Rhodophyta) based on phylogenetic principles. Opera Botanica 127: 1-221.

Description: Plant small, creeping, axes prostrate with erect branches bearing whorls of 2-4 equal or unequal branchlets (pinnae) and single gland cells terminal on rachides of pinnae. Pinnae variable in form, rachides always with small basal cell. Largest pinnae pinnately branched, distichous, flat, to 600 ┬Ám long. others reduced in form with shorter curved rachides and fewer (occasionally none) shorter outwardly-oriented pinnules. Uppermost pair of pinnules clasping the gland cell usually present. Most reduced pinnae towards base of thallus. Number of pinnae per axial cell varies from 2, as usual in A. butleriae, to 3-4 in A. preissii. Whorls of evenly spaced pinnae or opposite pairs of distichous-pinnate pinnae with 1-2 reduced pinnae side by side between them. Pinnules occasionally with short secondary branchlets. Procarp and carposporophyte as for Antithamnion with 4-celled carpogonial branches formed on basal (supporting) cells of 4-8 successive young pinnae near branch apices. Auxiliary cell, cut off from supporting cell, gives rise to gonimoblast cell with rounded groups of carposporangia. Spermatangial clusters on short pinnules usually towards base of pinnae. Tetrasporangia spherical, cruciate, borne in upward protrusions from basal cells of pinnae. Similar to Antithamnion in plant form, procarp and carposporophyte development and cruciate tetrasporangia. Distinct in pronounced morphological variation and gland cells terminal on rachides of pinnae.

Information contributed by: E.M. Wollaston. The most recent alteration to this page was made on 25 Jan 2017 by M.D. Guiry.

Comments: Common in southern Australia. Also recorded from Japan, West Indies, Solomon Islands, southern Africa and the Mediterranean. Probably more widespread than at present recognized. Usually epiphytic on larger algae.

Numbers of names and species: There are 5 species names in the database at present, of which 2 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
Wynne, M.J. & Schneider, C.W. (2010). Addendum to the synoptic review of red algal genera. Botanica Marina 53: 291-299.

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: 01 January 2001 by M.D. Guiry

Verified by: 25 January 2017 by M.D. Guiry

Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=35258

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 19 November 2019.

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