Seguenzaea Borzì, 1907

Holotype species: Seguenzaea sicula Borzì

Original publication and holotype designation: Borzì, A. (1907). I generi delle Stigonemacee. In: Atti del Congresso dei naturalisti italiani: promosso dalla Società italiana di scienze naturali, Milano, 15-19 settembre 1906. (Anon. Eds), pp. 370-375. Milano [Milan]: Società italiana di scienze naturali. Tipografia degli operai.

Description: Filamentous -thallose; filaments composed of trichomes and sheaths; trichomes of two types, torulous, creeping on the substrate and cylindrical, erect, joined parallel in densely agglomerated fascicles (macroscopically visible); creeping filaments uni- or (rarely) multiseriate, hypothallic, sometimes true branched (T-type of branches), with more or less barrel-shaped cells and solitary intercalary, barrel-shaped heterocytes; erect trichomes more or less cylindrical, constricted or unconstricted at cross walls, with solitary intercalary, usually cylindrical (sometimes very long) heterocytes. In both basal and particularly erect filaments common false branching, usually with one lateral branch (rarely with two branches), diverging at heterocytes. Sheaths thin, firm, usually not lamellated, colorless. Cells pale, olive or bright blue-green, with solitary distinct granules. Akinetes not known. Cell division mainly crosswise, sometimes asymmetric. Reproduction by 8-10-celled hormogonia, which separate serially from the ends of branches by help of necridic cells, by hormocytes (short ensheathed branches) and by solitary cells, clusters or 2-celled groups of cells, originating from the disintegrating old trichomes. Aerophytic and atmophytic species, described from wet walls and mosses, from the nature and glasshouses; known from Italy and Austria.

Information contributed by: J. Komárek. The most recent alteration to this page was made on 2023-03-06 by M.D. Guiry.

Taxonomic status: This name is of an entity that is currently accepted taxonomically.

Gender: This genus name is currently treated as feminine.

Most recent taxonomic treatment adopted: Strunecký, O., Ivanova, A.P. & Mares, J. (2022 '2023'). An updated classification of cyanobacterial orders and families based on phylogenomic and polyphasic analysis (Review). Journal of Phycology 59(1): 12-51.

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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Some of the descriptions included in AlgaeBase were originally from the unpublished Encyclopedia of Algal Genera, organised in the 1990s by Dr Bruce Parker on behalf of the Phycological Society of America (PSA) and intended to be published in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=47351

Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 06 March 2023. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 27 April 2024