Sebdenia (J.Agardh) Berthold, 1882
Lectotype species: Sebdenia monardiana (Montagne) Berthold
Original publication: Berthold, G. (1882). Über die Vertheilung der Algen im Golf von Neapel nebst einem Verzeichnis der bisher daselbst beobachteten Arten. Mittheilungen aus der Zoologischen Station zu Neapal 3: 393-536, 3 pls.
Request PDFType designated in: Schmitz, F. (1889). Systematische Übersicht der bisher bekannten Gattungen der Florideen. Flora oder Allgemeine botanische Zeitung 72: 435-456, pl. XXI.
Precise date of publication: 1 Sept 1882
Description: Plants are multiaxial and composed of a filamentous medulla surrounded by pseudoparenchymatous cortical layers with cells decreasing in size toward the exterior. Secondary pit connections are present, and inner cells are multinucleate. Carpogonial branches are 3-or 4-celled, directed outwardly, and located on inner cortical cells. Auxiliary cells are intercalary in cortical filaments separate from those bearing carpogonial branches. Fertilized carpogonia give rise directly to sparingly branched, septate connecting filaments that fuse with the auxiliary cells, either terminating or continuing growth to effect further diploidizations (Hansen 1989). Gonimoblast initials are single and oriented toward the thallus surface, the gonimoblasts forming compact masses composed mostly of carposporangia. A small fusion cell forms that incorporates the auxiliary and adjacent cells. Cystocarps are deeply embedded, protuberant, and surrounded by a lax hull of gametophytic tissue. Ostioles are apparently lacking in some species, or are rudimentary (Hansen 1989). Tetrasporophytes are isomorphic with gametophytes and produce cruciate tetrasporangia scattered in the outer cortex.
Information contributed by: G.T. Kraft. The most recent alteration to this page was made on 2021-08-28 by M.D. Guiry.
Taxonomic status: This name is of an entity that is currently accepted taxonomically.
Most recent taxonomic treatment adopted: Cormaci, M., Furnari, G. & Alongi, G. (2021). Flora marina bentonica del Mediterraneo: Rhodophyta - Rhodymeniophycidae II. Halymeniales, Nemastomatales, Peyssonneliales, Plocamiales, Rhodymeniales, Sebdeniales. Bollettino dell'Accademia Gioenia di Scienze Naturali di Catania 54(384): 9-342.
Comments: Plants of the largest species exceed 30 cm in length. Thalli are erect from crustose bases and are tubular to bladelike in habit. The texture of many of the species is soft and flaccid, some being gelatinous. Medullary filaments incorporate "ganglioid" cells (cells with radiating arms filled with highly refractive contents) that can bear "gland" cells. Codomier (1973) found that carpospores and tetraspores germinate to form discs that give rise to creeping filaments on which buds arise that develop into upright thalli. Codomier (1972) has also reported that fertilized carpogonia in one species first fuse with the supporting cell, which then gives rise to connecting filaments. Some species are reported to be monoecious, the mother cells producing 1-3 spermatangia and aggregated into surface patches. Most species are reported to form cruciate tetrasporangia, but Yamada (1938) describes those of one species as being both zonate and cruciate, with linking irregularly divided forms. Distribution: The type and 3 other species are endemic to the Mediterranean Sea, with other species occurring in the eastern Pacific from California to Baja California, Japan, and Peru. The most widespread species, S. polydactyla (Boergesen) Balakrishnan, occurs in India, South Australia, southern Japan, the Gulf of California and North Carolina. The Sebdeniaceae is a family consisting of 2 genera and 13 current species.
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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=33910
Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 28 August 2021. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 23 November 2024
