Willea Schmidle, 1900

Holotype species: Willea irregularis (Wille) Schmidle

Original publication and holotype designation: Schmidle, W. (1900). Algologische Notizen. XV. Allgemeine Botanische Zeitschrift für Systematik 6(12): 233-235.

Description: Thalli colonial, forming 2- or mostly 4-celled coenobia; these aggregated in compound colonies of up 100 or more cells in a single plane. Colonies embedded in structureless mucilaginous envelope. 4-celled coenobia with rhombic space in center. Cells not flattened in plane of coenobium, oval to oval-cylindrical, 6-15 x 4-6 µm, with broadly rounded ends. Cell walls smooth. Cells uninucleate; chloroplasts single and parietal with single pyrenoid that may be indistinct; according to some authors pyrenoids may be present or absent. Asexual reproduction by autospores; 2-4 per sporangium and organized into coenobia. Spore release by enlargement and eventual breakdown and dissolution of parental cell walls. Successive divisions for autospores at right angles. Flagellated stages and sexual reproduction unknown. Willea planktonic in freshwater, mostly in the littoral of lakes. Genus reported mostly from northern and eastern Europe with scattered reports from North America, Japan and Kerguelen Islands. Relationships of genus unclear. A second species, W. vilhelmii (and possibly a third) recognized by some authors based on presence or absence of pyrenoids and cell shape and number in colony. Thalli colonial, forming 2- or mostly 4-celled coenobia; these aggregated in compound colonies of up 100 or more cells in a single plane. Colonies embedded in structureless mucilaginous envelope. 4-celled coenobia with rhombic space in center. Cells not flattened in plane of coenobium, oval to oval-cylindrical, 6-15 x 4-6 µm, with broadly rounded ends. Cell walls smooth. Cells uninucleate; chloroplasts single and parietal with single pyrenoid that may be indistinct; according to some authors pyrenoids may be present or absent. Asexual reproduction by autospores; 2-4 per sporangium and organized into coenobia. Spore release by enlargement and eventual breakdown and dissolution of parental cell walls. Successive divisions for autospores at right angles. Flagellated stages and sexual reproduction unknown. Willea planktonic in freshwater, mostly in the littoral of lakes. Genus reported mostly from northern and eastern Europe with scattered reports from North America, Japan and Kerguelen Islands. Relationships of genus unclear. A second species, W. vilhelmii (and possibly a third) recognized by some authors based on presence or absence of pyrenoids and cell shape and number in colony.

Information contributed by: D. Garbary and E. Hegewald. The most recent alteration to this page was made on 2021-01-16 by Wendy Guiry.

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

Most recent taxonomic treatment adopted: John, D.M., Wynne, M.J. & Tsarenko, P.M. (2014). Reinstatement of the genus Willea Schmidle 1900 for Crucigeniella Lemmermann 1900 nom. illeg. (Chlorellales, Trebouxiophyceae, Chlorophyta). Phytotaxa 167(2): 212-214, no figs.

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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.

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Citing AlgaeBase
Cite this record as:
Wendy Guiry in Guiry, M.D. & Guiry, G.M. 16 January 2021. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 23 November 2024