Chrysymenia J.Agardh, 1842
Lectotype species: Chrysymenia ventricosa (J.V.Lamouroux) J.Agardh
Original publication: Agardh, J.G. (1842). Algae maris Mediterranei et Adriatici, observationes in diagnosin specierum et dispositionem generum. pp. [i]-x, 1-164. Parisiis [Paris]: Apud Fortin, Masson et Cie.
Type designated in: Schmitz, F. (1889). Systematische Übersicht der bisher bekannten Gattungen der Florideen. Flora oder Allgemeine botanische Zeitung 72: 435-456, pl. XXI.
Description: Thallus with a discoid holdfast and erect or decumbent, tubular, saccate or compressed, hollow, firmly gelatinous fronds. Structure multiaxial, cortex of 2-3 layers of small cells. Medulla consisting of cavities filled with a weak mucilage, secretory cells borne on cells lining the cavities. Gametangial plants dioecious; spermatangial sori superficial, scattered, spermatangia cut off terminally from elongated initials modified from cortical cells. Procarpic, carpogonial branches in cortex, 4-celled, formed on a multinucleate supporting cell with a 2-celled auxiliary cell branch, gonimoblast developing outwards from a fusion cell. Cystocarps ostiolate, scattered, never coronate, protruding outwards and inwards or outwards only, most cells forming carposporangia in 2-3 lobes of different ages, tela arachnoidea absent. Tetrasporangia formed in an intercalary position from cortical filaments, scattered. Spores regularly cruciately arranged. Nothing is known of the growth of species of Chrysymenia in culture, although they are likely to have a 'Polysiphonia-type' life history. Kajimura (1977) germinated the tetraspores of C. grandis from Japan and describes the developmental pattern of the tetrasporelings.
Information contributed by: M.D. Guiry. The most recent alteration to this page was made on 2018-07-06 by M.D. Guiry.
Taxonomic status: This name is of an entity that is currently accepted taxonomically.
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: Kylin (1931) referred flattened or flat species of Chrysymenia with "internal rhizoids" in the medullary cavities to the genus Cryptarachne, previously recognized as a subgenus or section of Chrysymenia. This was followed by Taylor (1960) and other authors. Børgesen (1910, 1920) had, however, earlier observed that the type species of Chrysymenia, C. ventricosa, and the type species of Cryptarachne, C. agardhii(Harvey) Kylin both had internal rhizoids in his material. Okamura (1936, cited by Abbott and Littler 1969), working with Japanese species, also did not recognise Cryptarachne as a genus because his specimens showed both the presence and absence of rhizoids. Abbott and Littler (1969) reached a similar conclusion with Hawaiian material. The genus Chrysymenia is well characterized on the basis of entirely hollow fronds, the absence of regular constrictions or diaphragms, and the absence of secretory cells on the rhizoidal cells in the medulla. Chrysymenia is closely related to Botryocladia (q.v.) from which it differs in being entirely hollow except for the basal attachment structure. Most species of Chrysymenia are found in tropical or subtropical waters. Plants occur mainly in the subtidal at depths of up to 50 m.
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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=33249
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 06 July 2018. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 04 December 2023