Rivularia C.Agardh ex Bornet & Flahault, 1886, nom. cons.
Lectotype species: Rivularia atra Roth ex Bornet & Flahault
Original publication: Bornet, É. & Flahault, C. (1886). Revision des Nostocacées hétérocystées contenues dans les principaux herbiers de France. Annales des Sciences Naturelles, Botanique, Septième série 3: 323-381.
Type designated in: Geitler, L. (1942). Schizophyta: Klasse Schizophyceae. In: Die natürlichen Pflanzenfamilien, Sweite Auflage. (Engler, A. & Prantl, K. Eds) Vol.1b, pp. 1-232. Leipzig: Wilhelm Engelmann.
Description: Filaments heteropolar, differentiated into basal and apical parts, simple, joined parallely into firm, at the beginning of the vegetation cycle hemispherical or spherical, later sometimes vaste, flat, macroscopic, irregular strata, up to several cm or dm in diameter and several mm thick; strata are layered (sometimes with several layers), with densely agglomerated trichomes, oriented by their bases with heterocytes to the substrate and by the apical hair-like parts to the surface of the colony. Strata are gelatinous up to leathery or intensely incrusted by calcium carbonate, always covering the substrate. Trichomes +/- cylindrical, constricted or unconstricted at the cross walls, dividing at intercalar heterocytes: the divided trichomes separate one from another, but remain parallely located within the mother sheaths in the colony. Hairs are composed from the narrow, long, hyaline cells. Sheaths firm, sometimes lamellated, colourless or yellow-brown, enveloping all the ?daughter? trichomes, which produce their own.
Information contributed by: J. Komárek (1992).. 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.
Comments: Cell division perpendicularly to the long axis of a trichome, later in meristematic zones. Reproduction by disintegration of trichomes whithin colonies and heterocytes and by hormogonia, separating after the separation of the hair by the help of necridic cells and sometimes liberating from the colonies. The genus is typified by a marine species from NE Atlantic.
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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=42977
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 06 December 2023