Sciadophycus E.Y.Dawson, 1944
Holotype species: Sciadophycus stellatus E.Y.Dawson
Original publication and holotype designation: Dawson, E.Y. (1945). Some new and unreported sublittoral algae from Cerros Island, Mexico. Bulletin of the Southern California Academy of Sciences 43(3): 102-112, pls 20, 21.
Request PDFDescription: Thallus peltate, blades arising from a branched or unbranched, cylindrical stipe, initially simple and circular, later becoming stellate, reattaching by means of specialised structures at the tips of the 10-14 stellate arms to form a new blade and stipe, mature plants thereby spreading and imbricate. Construction multiaxial, cortex of 1-2 layers of small cells. Medulla of a single layer of large, thick-walled, colourless cells.
Spermatangia unknown.
Information contributed by: M.D. Guiry. The most recent alteration to this page was made on 2010-10-08 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: Neushul and others (1967) found that plants of Sciadophycus stellatus doubled in wet weight in 30 days at 18-19%C under constant illumination and that the upper surface of blades orientate themselves perpendicularly to the plane of the incident light in what appears to be a phototropic response, whereas stipes grew away from the light. Two other genera of Rhodymeniales include species that form peltate blades: Halichrysis (q.v.), and Maripelta (q.v.).Halichrysis has a polystromatic medulla and, although the peltate blades may become imbricate, they are not stellate in appearance. In Maripelta, the blades are not imbricate and reattachment does not take place, cystocarps lack a tela arachnoidea and the tetrasporangia are formed in an intercalary position. Sciadophycus stellatus is only known at depths of 13-50 m from the Californian Channel Is. south to Baja California.Reports of its occurrence south to the Galápagos Is. (Abbott and Hollenberg 1976: 547) require confirmation.In southern California, it is usually found below the canopies of kelp forests, and appears to be adapted to the low irradiance conditions found in such situations.
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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.
Linking to this page: https://www.algaebase.org/search/genus/detail/?genus_id=42465
Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 08 October 2010. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 19 April 2024
