Roya West & G.S.West, 1896

Holotype species: Roya obtusa (Brébisson) West & G.S.West

Original publication and holotype designation: West, W. & West, G.S. (1896). On some new and interesting freshwater algae. Journal of the Royal Microscopical Society 16: 149-165, 2 pls.

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Description: Cells solitary, small to medium sized (22-195 µm), elongate-cylindric (length 4-60 times width), slightly curved or straight, with broadly rounded or truncate ends. Chloroplast an axial ribbon with row of up to 12 pyrenoids; cells with two chloroplast observed. Nucleus parietal at middle of cell (often in median notch in chloroplast), or between chloroplasts, if two present. Ultrastructure of cell wall two layered. Asexual reproduction only by transverse cell division. Sexual reproduction by conjugation known for 2 species; homothallic, without conjugation tube in R. obtusa. Naked gametes exite gametangia through pore at tip of short papilla. Zygotes form midway between gametangia; mature zygospores spherical, smooth-walled. Gamete nuclei remain distinct in dormant zygospore; karyogamy possibly at germination, similar to Netrium. Zygospore germination, however, not observed.

Information contributed by: J.F. Gerrath. The most recent alteration to this page was made on 2018-07-12 by M.D. Guiry.

Taxonomic status: This name is of an entity that is currently accepted taxonomically.

Most recent taxonomic treatment adopted: Guiry, M.D. (2013). Taxonomy and nomenclature of the Conjugatophyceae (=Zygnematophyceae). Algae. An International Journal of Algal Research 28: 1-29.

Comments: Roya usually in low numbers in oligotrophic, aquatic habitats or in Sphagnum bogs in Europe, Soviet Union, North America and South America; occasional records from subaerial habitats (on wet rocks or among mosses) in alpine environments.

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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Some of the descriptions included in AlgaeBase were originally from the unpublished Encyclopedia of Algal Genera, organised in the 1990s by Dr Bruce Parker on behalf of the Phycological Society of America (PSA) and intended to be published in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=43558

Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 12 July 2018. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 03 December 2024