Lychnothamnus (Ruprecht) A.Braun, 1856

Holotype species: Lychnothamnus barbatus (Meyen) Leonhardi

Original publication and holotype designation: Braun, A. (1857). Über Parthenogenesis bei Pflanzen. Abhandlungen der Koniglichen Akademie der Wissenschaften zu Berlin 1856: 311-376.

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Description: Erect, branched plants > 30 cm in length, attached to substratum with rhizoids. Rhizoids numerous, multicellular, branching, and colorless. Primary axes with alternating sequence of nodal and internodal cells developed from apical cell. Each apical cell derivative divides transversely and the daughter cells develop into a multicellular nodal complex with 9-12 peripheral cells and its internodal cell, respectively. Each node bears a whorl determinate bra nchlets 2-many cells long; stipulodes two per branchlet. Indeterminate axes develop singly in the axes of branchlets at scattered nodes. Internodal cells enlarge to several cm in length. Cortex poorly developed on internodes, absent on branchlets. Cells mostly uninucleate, however, internodal cells with a few large irregular nuclei produced by amitosis. Cytoplasm distinctly layers with external stationary layer with rows of helicoidally aligned chloroplasts (ectoplasm) and internal streaming layer with nuclei, mitochondria (endoplasm); cells with large central vacuole. Asexual and sexual reproduction similar to Chara and Lamprothamnion. Sexual reproduction always oogamous with gametes produced in complex, multicellular antheridia and oosporangia. Oosporangia flanked on either side with antheridia. Oosporangia producing a single sterile cell similar to Chara. Chromosomes counted in only one species with n = 14. Life history presumably zygotic with meiosis occurring during oospore germination. Lychnothamnus confined to freshwater in Eurasia and Australia with one species endemic to Europe and two endemic to India. Based on vegetative and reproductive morphology, Lychnothamnus is related to Chara. Sperm ultrastructure remains unstudied and should provide key information on relationships with Chara, Lamprothamnion and Nitellopsis.

Information contributed by: D. Garbary. The most recent alteration to this page was made on 2020-03-10 by M.D. Guiry.

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

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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=43353

Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 10 March 2020. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 31 January 2023

 
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