Klebsormidium P.C.Silva, Mattox & W.H.Blackwell, 1972
Holotype species: Klebsormidium flaccidum (Kützing) P.C.Silva, Mattox & W.H.Blackwell
Original publication and holotype designation: Silva, P.C., Mattox, K.R. & Blackwell, W.H., Jr (1972). The generic name Hormidium as applied to green algae. Taxon 21: 639-645.
Request PDFDescription: Filaments uniseriate and unbranched, without polar differentiation. Free-floating or attached via hyaline, gelatinous, spherical-like holdfast surrounding basal cell. Cells basically cylindrical. Cell wall thin and smooth, under adverse conditions sometimes markedly thickened, lamellate, and verrucose, simultaneously with H-pieces wrapping transverse cell walls. Chloroplast single and parietal, laminate or girdle-shaped, often withdrawn and then elliptical or discoid, incompletely encircling cell lumen and not lobed, usually occupying not more than one half of cell periphery. Pyrenoid single, embedded in center of chloroplast, usually surrounded by distinct starch envelope. Asexual reproduction by biflagellate zoospores or by walled aplanospores, sometimes following dormancy.
Zoospores dorsiventral with flagella subapically and asymmetrically inserted; stigma absent. Zoospores formed singly in unspecialized cells, escaping through distinct lateral pore in cell wall, producing no holdfast on germination. Vegetative multiplication by fragmentation into unicells ("Vermehrungsakineten"), or few-celled fragments. Akinetes infrequent, elliptical , surrounded by thick membrane enclosing cell contents rich in assimilates. Sexual reproduction purportedly by anisogamous fusion of biflagellate spindle-shaped gametes with distinct stigmas.
Information contributed by: G.M. Lokhorst & M.D. Guiry. The most recent alteration to this page was made on 2024-04-02 by M.D. Guiry.
Taxonomic status: This name is of an entity that is currently accepted taxonomically.
Most recent taxonomic treatment adopted: Bierenbroodspot, M.J., Darienko, T., de Vries, S., Fürst-Jansen, J.M.R., Buschmann, H., Pröschold, T., Irisarri, I. & de Vries, J. (2024 '2023'). Phylogenomic insights into the first multicellular streptophyte. Current Biology 34: [1-12].
Comments: Klebsormidium was proposed in 1972 to resolve confusion in application and status of Hormidium. Earlier proposals to replace Hormidium by, e.g. Hormococcus Chodat, Pseudoulothrix Pascher and Chlorhormidium Fott, were illegitimate or inadequate. Ultrastructural studies showed papilla formation during sporogenesis on cell wall, marking rupture point in zoospore release; cytokinesis by furrowing sometimes associated with array of ill-defined cytokinetic microtubules; flagellar root system in zoospores asymmetric, characterized by presence of a so-called MLS (multilayered structure). Accordingly, Klebsormidium associated with charophycean evolutionary line, this also supported by catalase activity of peroxisomes. Karyological studies indicate chromosome numbers of n= 22-26.
Klebsormidium occurs mostly in soil and on moist substrates but aquatic species are known; one species is marine.
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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=42757
Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 02 April 2024. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 22 November 2024
