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Rhodymeniocolax Setchell, 1923

Empire Eukaryota
Kingdom Plantae
Subkingdom Biliphyta
Phylum Rhodophyta
Subphylum Eurhodophytina
Class Florideophyceae
Subclass Rhodymeniophycidae
Order Rhodymeniales
Family Rhodymeniaceae

Holotype species: Rhodymeniocolax botryoideus Setchell

Original publication and holotype designation: Setchell, W.A. (1923). Parasitic Florideae, II. University of California Publications in Botany 10: 393-396.
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Taxonomic status: currently recognized as a distinct genus.

Gender: This genus name is currently treated as masculine.

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.

Nomenclatural notes
Monotypic when first introduced. - (24 Jan 2017) - M.D. Guiry

Description: Thallus inconspicuous, pustular, verrucose or stellate, base consisting of supposedly parasitic filaments penetrating the host. Erect fronds with short branches, pinkish, consistency slightly softer than host. Construction multiaxial, cortex 1-3 cells in thickness. Medulla pseudoparencymatous consisting of relatively large radially elongated cells. Spermatangial plants unknown. Procarpic, carpogonial branches 4-celled borne on a large multinucleate supporting cell with a 2-celled auxiliary cell branch, gonimoblast developing outwards often with 2-3 lobes, almost all cells forming carposporangia. Cystocarps hemispherical, large and protruding, ostiolate, scattered, tela arachnoidea absent. Tetrasporangia scattered, formed in an intercalary position in unmodified cortex. Spores regularly cruciately arranged.

Information contributed by: M.D. Guiry. The most recent alteration to this page was made on 24 Jan 2017 by M.D. Guiry.

Comments: Species of the genus are found exclusively on Rhodymenia, on which it is generally assumed that they are parasitic. However, the pinkish nature of the plants suggests that they are capable of at least some photosynthesis. The structure and reproduction of Rhodymeniocolax is very similar to that of Rhodymenia; the sizes of the reproductive structures are, however, very much smaller. Two other parasitic genera are found in the Rhodymeniaceae: Faucheocolax and Gloiocolax (q.v.). These are similar to Rhodymeniocolax in that their structure and reproduction closely resemble that of their hosts. Rhodymeniocolax botryoidea is known from the western coast of North America (N. Washington to central and southern California), where it grows mainly on Rhodymenia pacifica Kylin and an undescribed species from the British Isles and France growing on R. pseudopalmata and R. holmesii Ardissone (Irvine and Guiry in Irvine 1983). A further species, possibly more closely related to the unnamed British species, was described recently by Womersley (1996) from R. australis Sonder plants from South Australia and Victoria.

Numbers of names and species: There are 3 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):

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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: 24 January 2017 by M.D. Guiry

Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=42288

Citing AlgaeBase
Please cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 2021. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 17 October 2021.

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