Pseudochorda Yamada, Tokida & Inagaki, 1958

Holotype species: Pseudochorda nagaii (Tokida) Inagaki

Original publication and holotype designation: Inagaki, K.-I. (1958). A systematic study of the order Chordariales from Japan and its vicinity. Scientific Papers of the Institute of Algological Research, Faculty of Science, Hokkaido Imperial University 4(2): 87-197, 11 pls.

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Description: Annual, growing during spring and winter, epilithic, lower intertidal to upper subtidal. Sporophyte gregarious on small discoid holdfast, up to 50 cm in length, olive to dark brown, solid when young, becoming hollow later. Erect thallus composed of rather dense medullary layer, 4-6 celled paraphyses and narrow obovate unilocular sporangia, with or without hairs according to the species. Special mucilagenous organs absent. Chloroplasts many, discoid, without pyrenoids. Life history heteromorphic between macroscopic polystichous sporophyte and branched filamentous gametophyte. Gametophytes oogamous, dioecious but sexually monomorphic (P. nagaii) or dimorphic (P. gracilis). Zoospores from unilocular sporangia teardrop-shaped, normally biflagellated, with stigma. Germination unipolar forming emptied embryospore. Antheridia formed solitary or in cluster. Sperm almost colorless containing several reduced chloroplast without stigma, with longer posterior flagellum. Oogonia terminal on fertile branches. Zygotes develop attached at the mouth of the oogonia. First several divisions occur transversely, then become polystichous, terete, form paraphyses and unilocular sporangia. In P. nagaii, gametophytes mature in 5°C short day condition. Sporophytes grow in 5-15°C and mature in 5-10°C.

Information contributed by: H. Kawai. The most recent alteration to this page was made on 2022-06-26 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: Distributed in cold current area of eastern Asia (Aleutian Islands, Southern Kuriles, Southern Saghalien, Japan Sea coast of USSR).

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Some of the descriptions included in AlgaeBase were originally from the unpublished Encyclopedia of Algal Genera, organised in the 1990s by Dr Bruce Parker on behalf of the Phycological Society of America (PSA) and intended to be published in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

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M.D. Guiry in Guiry, M.D. & Guiry, G.M. 26 June 2022. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway.; searched on 19 May 2024

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