Janczewskia Solms-Laubach, 1877

Holotype species: Janczewskia verruciformis Solms-Laubach

Currently accepted name for the type species: Laurencia verruciformis (Solm-Laubach) M.Preuss, Diaz-Tapia, Verbruggen & Zuccarello

Original publication and holotype designation: Solms-Laubach, H. (1877). Note sur Janczewskia, nouvelle Floridée parasite du Chondria obtusa. Mémoires de la Société Nationale des Sciences Naturelles et Mathématiques de Cherbourg 21: 209-224, pl. 3.

Description: Hemiparasites on Laurencia and Chondria; 3 basic types of thalli: a nodule-like mass of tissue emerging from host branches, nodules from which radiate simple erect branches, and a group of radiating compound free branches without a distinct basal nodule; species are separated into these 3 groups. Filaments of parasite tissue penetrate host and establish pit connections with host cells. Thalli basically polysiphonous becoming pseudoparenchymatous at early stage; apical cell often obscure but in some species in a pit surrounded by reduced trichoblasts. Lenticular wall thickenings present in cell walls in some species. Tetrasporangia distal on thallus lobes, either subepidermal and cut off abaxially or on short stalks within conceptacle-like pits, interspersed with branched trichoblasts. Cystocarps spheroidal, terminating thallus lobes. Spermatangia terminating branchlets of plumose, trichoblast-like branches on walls of conceptacle-like depressions on thallus. Emend. Nam 2022: 305.

Information kindly contributed by R.E. Norris but may now be outdated.

Taxonomic status: This name is currently regarded as a synonym of Laurencia.

Most recent taxonomic treatment adopted: Preuss, M., Díaz-Tapia, P., Verbruggen, H. & Zuccarello, G.C. (2023). Gene-rich plastid genomes of two parasitic red algal species, Laurencia australis and L. verruciformis (Rhodomelaceae, Ceramiales), and a taxonomic revision of Janczewskia. Journal of Phycology 59(5): 950-962.

Comments: On Laurencia and Chondria in temperate to tropical shores of all oceans.

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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Some of the descriptions included in AlgaeBase were originally from the unpublished Encyclopedia of Algal Genera, organised in the 1990s by Dr Bruce Parker on behalf of the Phycological Society of America (PSA) and intended to be published in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:
G.M. Guiry in Guiry, M.D. & Guiry, G.M. 19 February 2024. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 24 November 2024