Thuretia Decaisne, 1844
Holotype species: Thuretia quercifolia Decaisne
Original publication and holotype designation: Decaisne, J. (1844). Note sur quelques algues à frondes réticulées. Annales des Sciences Naturelles, Botanique, Sér. 3 2: 233-236.
Request PDFDescription: Thallus erect, sympodially developed, dorsiventrally organized, the upper portions apppearing leafy or plumose due to flattened or terete networks of pseudolaterals. Indeterminate axes terete or slightly compressed, alternately branched and alternately producing determinate pseudolateral branch systems or sympodia from each polysiphonous segment. Pseudolaterals pigmented, distichously placed, and monosiphonous except at bases, once to several times alternately to subdichotomously branched, upper portions formed into an anastomosing network which surrounds the axes. Axial cells surrounded by 4 periaxials which quickly cut off corticating cells that give rise to short descending filaments which pit-connect with lower periaxial and corticating cells, collectively forming heavy cortication obscuring the periaxials.
Dioecious, spermatangia formed on terminal swollen, subglobose filaments of pseudolaterals, overall forming organized globose to ovoid stichidia. Procarps formed on basal segments of pseudolaterals or determinate sympodia on the female plant, these also bearing monosiphonous branching networks above. Procarps consist of a 4-celled carpogonial branch and 2 sterile groups of cells borne on the supporting cell all covered by a pericarp before fertilization. After fertilization, the carpogonium cuts off a connecting cell which fuses with the central cell of the carpogonial branch and then auxiliary cell just cut off the supporting cell. The fusion cell generates monopodial gonimoblast filaments with terminal, then lateral carposporangia. Carposporophytes surrounded by large, corticated pericarps with prominent necks which penetrate the monosiphonous network. Four to five tetrahedral sporangia produced in whorls, forming 2 rows within basal portions of pseudolaterals or main axes forming1-3 times branched stichidia subtending monosiphonous networks. Tetrasporangia completely enclosed by cover cells at maturity.
Information contributed by: C.W. Schneider. The most recent alteration to this page was made on 2010-10-06 by M.D. Guiry.
Taxonomic status: This name is of an entity that is currently accepted taxonomically.
Most recent taxonomic treatment adopted: Schneider, C.W. & Wynne, M.J. (2007). A synoptic review of the classification of red algal genera a half a century after Kylin's "Die Gattungen der Rhodophyceen". Botanica Marina 50: 197-249.
Comments: Shallow subtidal from Australia and the Caribbean.
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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=35503
Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 06 October 2010. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 25 April 2024
