155,805 species and infraspecific names are in the database, 21,968 images, 60,221 bibliographic items, 439,336 distributional records.

Eudesme J.Agardh, 1882

Classification:
Empire Eukaryota
Kingdom Chromista
Phylum Ochrophyta
Class Phaeophyceae
Subclass Fucophycidae
Order Ectocarpales
Family Chordariaceae

Lectotype species: Eudesme virescens (Carmichael ex Berkeley) J.Agardh

Original publication:Agardh, J.G. (1882). Till algernes systematik. Nya bidrag. (Andra afdelningen.). Lunds Universitets Års-Skrift, Afdelningen for Mathematik och Naturvetenskap 17(4): 1-134, 3 plates.
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Type designated in De Toni, G.B. (1891). Sylloge algarum omnium hucusque cognitarum. Vol. II. Sylloge Bacillariearum. Sectio I. Rhaphideae. pp. [i-iii]. [i]-cxxxii, 1-490. Patavii [Padua]: Sumptibus auctoris.
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Taxonomic status: currently recognized as a distinct genus.

Description: Plants epilithic in intertidal to upper subtidal zone, solitary or loosely caespitose, up to 30 cm in height, 1-2 times branched, soft, gelatinous, haplostichous, solid, attached on the substrata by small discoidal rhizoidal holdfast. Erect thallus composed of multiaxial medullary filaments, giving rise to lateral colorless branched filaments bearing pigmented assimilatory filaments. Medullary filaments very loosely bound together, composed of colorless large cells 40-70 _m in diameter, 1.5-2.5 times as long as the diameter, constricted at the cross walls. Assimilatory filaments slender, branched, isodiametric, cylindrical below, becoming slightly swollen above, as long as 15-20 cells, sometimes with short branchlets near terminal part. Each cell contains several disc-shaped chloroplasts with pyrenoid. Phaeophycean hairs present. Unilocular sporangia form from basal part of assimilatory filaments, irregular in shape, sessile, 80-120 _m ( 50-75 _m in size. Plurilocular sporangia not detected on erect thalli. In Japanese E. virescens, asexual direct type of life history is reported (Kawai 1986). Unispores 7-7.5 _m x 4.5-5 _m in size, normally biflagellated, pear-shaped containing a single chloroplast with stigma, negatively phototactic, germinate unipolarly without leaving emptied embryospore, develop into bushy microthalli which directly form multiaxial macrothallus bearing unilocular sporangia. There was no clear regulation of life history by temperature or photoperiod, although macrothalli developed better under long day conditions. On the other hand, Cole (1967) reported sexual reproductions in the microthalli derived from unispores, however, zygotes developed into microthalli again and did not form macrothalli. Cole reported chromosome counts of 2n=20 (sporophyte), n=10 (gametophyte) and Kawai (1986) reported n=10-12 through the life history. Plants epilithic in intertidal to upper subtidal zone, solitary or loosely caespitose, up to 30 cm in height, 1-2 times branched, soft, gelatinous, haplostichous, solid, attached on the substrata by small discoidal rhizoidal holdfast. Erect thallus composed of multiaxial medullary filaments, giving rise to lateral colorless branched filaments bearing pigmented assimilatory filaments. Medullary filaments very loosely bound together, composed of colorless large cells 40-70 _m in diameter, 1.5-2.5 times as long as the diameter, constricted at the cross walls. Assimilatory filaments slender, branched, isodiametric, cylindrical below, becoming slightly swollen above, as long as 15-20 cells, sometimes with short branchlets near terminal part. Each cell contains several disc-shaped chloroplasts with pyrenoid. Phaeophycean hairs present. Unilocular sporangia form from basal part of assimilatory filaments, irregular in shape, sessile, 80-120 _m ( 50-75 _m in size. Plurilocular sporangia not detected on erect thalli. In Japanese E. virescens, asexual direct type of life history is reported (Kawai 1986). Unispores 7-7.5 _m x 4.5-5 _m in size, normally biflagellated, pear-shaped containing a single chloroplast with stigma, negatively phototactic, germinate unipolarly without leaving emptied embryospore, develop into bushy microthalli which directly form multiaxial macrothallus bearing unilocular sporangia. There was no clear regulation of life history by temperature or photoperiod, although macrothalli developed better under long day conditions. On the other hand, Cole (1967) reported sexual reproductions in the microthalli derived from unispores, however, zygotes developed into microthalli again and did not form macrothalli. Cole reported chromosome counts of 2n=20 (sporophyte), n=10 (gametophyte) and Kawai (1986) reported n=10-12 through the life history.

Information contributed by: H. Kawai. The most recent alteration to this page was made on 20 Jun 2014 by M.D. Guiry.

Numbers of names and species: There are 8 species names in the database at present, as well as 1 infraspecific names. Of the species names, 5 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.

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: 28 December 2000 by M.D. Guiry

Verified by: 20 June 2014 by M.D. Guiry

Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=37342

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 16 July 2019.

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