Desmosiphon Borzì, 1907

Holotype species: Desmosiphon maculans 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: Thallus joined to the substrate, crusty, more or less of circular outline, forming circular dark reddish -black spots, which later sometimes become confluent by their margins. Basal part composed of "chroococcoid" mass of densely agglomerated cells enveloped by their own mucilaginous, sometimes lamellated sheaths, occasionally arranged in pseudofilamentous rows, and forming erect filaments repeatedly pseudodichotomously and laterally branched, branching types: V and T. Erect trichomes uniseriate, rarely biseriate. Basal cells more or less spherical or polygonal-rounded, cells in trichomes barreliform, shorter or (at the ends) longer than wide. Sheaths thin, but distinct, colorless or (when old) yellow or yellow-brown. Heterocytes and akinetes missing. Cells divide irregularly in three or more planes in basal parts, and usually crosswise in erect trichomes, with numerous lateral divisions. Reproduction by planocytes, which separate from terminal parts of trichomes and escape from sheaths, and by free clusters of several cells enveloped by mucilaginous envelopes. The species grows on submerged freshwater substrates. It was described from Italy (Sicily wet and submerged rocks with streaming water) and later was found epilithic and epiphytic in littoral of lakes in Sweden. Ecological differences and both distant localities make genotype identity of both these populations uncertain. Sometimes joined with the genus Nematoplaca.

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 masculine.

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=44122

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 01 May 2024