Isthmoplea Kjellman, 1877

Holotype species: Isthmoplea sphaerophora (Carmichael ex Harvey) Kjellman ex Gobi

Original publication and holotype designation: Kjellman, F.R. (1877). Über die Algenvegetationen des Murmanschen Meeres av der Westküste von Nowaja Semlja und Wajgatsch. Nova Acta Regiae Societatis Scientiarum Upsaliensis, Series 3 Vol. ext. ord.(Art. XII): 1-86, 1 table.

Description: The macrothallus consists of uniseriate and parenchymatous parts. Longitudinal divisions occur simultaneously in the same cell. Quite often 2 (sometimes more) parallel divisions occur, and the outermost cells may develop into 2 unilocular sporangia, a unilocular sporangium and a lateral or 2 laterals. These various combinations are thus separated by the medial cell. This longitudinal division pattern is different from that in Fosliea. In the last mentioned genus the longitudinal walls are formed asynchronously. The longitudinal growth is diffuse intercalary. True phaeophycean hairs are absent. The swarmers from the unilocular sporangia develop into microthalli. In some strains the microthalli carry plurilocular sporangia (Edelstein and others 1971, Pedersen 1975, Jónsson 1977). New macrothalli develop from these pseudostreblonematoid microthalli and the new generation also carries unilocular sporangia.

Information contributed by: P. M. Pedersen. The most recent alteration to this page was made on 2021-11-02 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: Silberfeld, T., Rousseau, F. & Reviers, B. de (2014). An updated classification of brown algae (Ochrophyta, Phaeophyceae). Cryptogamie Algologie 35(2): 117-156, 1 fig., 1 table.

Comments: The species is represented by plants at various ploidy levels within its distribution area. Plants from Norway have 24 chromosomes, from Greenland 8, and from Iceland 4 (Rueness 1974, Pedersen 1975, Jónsson 1977, respectively).

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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Some of the descriptions included in AlgaeBase were originally from the unpublished Encyclopedia of Algal Genera, organised in the 1990s by Dr Bruce Parker on behalf of the Phycological Society of America (PSA) and intended to be published in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=37577

Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 02 November 2021. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 22 November 2024