Trichogloea Kützing, 1847

Holotype species: Trichogloea requienii (Montagne) Kützing

Original publication and holotype designation: Kützing, F.T. (1847). Diagnosen und Bemerkungen zu neuen oder kritischen Algen. Botanische Zeitung 5: 1-5, 22-25, 33-38, 52-55, 164-167, 177-180, 193-198, 219-223.

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Description: Plants are multiaxial, calcified, mucosoid, often with simple axes and few branches, or radially branched and sometimes becoming pinnately arranged when dried, with few to many orders of branching; when living, the mucus layer is as much as 3-4 times wider than the calcified axial core, but it disappears upon drying; the medulla is the same or slightly larger in diameter than the combined cortical filaments; the primary medullary filaments consist of a narrow inner core of filaments 20-45 µm (larger in T. herveyi) in diameter, 2-4 times the diameter of the slender filaments and numerous rhizoids of the outer core; lower cortical filaments form a plexus in some species before radially forming large fascicles of filaments, these mostly with elongate, little-divided branches; older filaments have cylindrical lower cells for approximately half their length, the distal cells more pigmented, tear-drop shaped to ellipsoid or moniliform; and younger filaments (in the type species) occurring at the bases of older ones have narrow cells approximately 3-4 µm in diameter, these filaments contain young carpogonial branches that, after fertilization, elongate along with vegetative filaments toward the surface. Deciduous, 1-2 colorless hairs are commonly attached to terminal cortical cells; these are surrounded by and often immersed in a thick mucosoid material, and are more abundant on female gametophytes than on male gametophytes. Young plants often occur with spermatangia near the apices before the appearance of carpogonial branches (and are, therefore, protandrous); while other plants have both sexes appearing simultaneously at the same level of development. Spermatangia arise in conspicuous clusters on several terminal or subterminal cortical cells; these are sometimes restricted to intercalary positions. Carpogonial branches1 arise in positions similar to vegetative branches, the distal 2-4 cells modified, with the terminal carpogonium having a broad base and distally narrowing to a sharp point and bearing a trichogyne; the 23 cells below this have a slightly different shape relative to the unmodified cells at the base of the carpogonial filament; all modified cells stain more intensely than the proximal unmodified cells. Carpogonial filaments appear to be formed slightly later than the main assimilatory filaments; that is, after the pattern of elongation and branching has been established. Sterile filaments, consisting of branched or unbranched shorter filaments, form laterally from cells below the hypogynous cell; these arise as the carpogonial branch develops in T. requienii; they are delayed in T. herveyi, and are almost completely lacking in T. lubrica. The sterile filaments never cover the gonimoblast and are, therefore, not involucrate. All or only the 1-2 distal cells of the carpogonial branch fuse as the carposporophyte matures, or fusion is lacking. Tetrasporophytes are not known, but are probably similar to the filamentous microscopic phases known for species of Liagora.

The most recent alteration to this page was made on 2010-10-05 by M.D. Guiry.

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

Most recent taxonomic treatment adopted: Abbott, I.A. & Huisman, J.M. (2005). Studies in the Liagoraceae (Nemaliales, Rhodophyta) I. The genus Trichogloea. Phycological Research 53(2): 149-163.

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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=34218

Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 05 October 2010. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 30 December 2024

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