Egregia Areschoug, 1876

Holotype species: Egregia menziesii (Turner) Areschoug

Original publication and holotype designation: Areschoug, J.E. (1876). De tribus Laminarieis (Egregia Aresch., Eisenia Aresch., Nereocystis) et de Stephanocystide osmundacea (Turn.). Trevis. observationes praecursorias offert. Botaniska Notiser 1876: 65-73.

Description: Sporophyte perennial. Conical holdfast with branched haptera. Stipe cylindrical to flattened, irregularly branched near base. Each branch become differentiated into a ligulate stipe portion, the rhachis, and the blade portion. Both rhachis and lamina increase in length, but the lamina much less than the rhachis. Both bear outgrowths on each margin throughout most of the length. The outgrowths may have different forms and functions: some become stipitate pneumatocysts, some ligulate and sterile blades and some small blades bearing sori on both surfaces (sporophylls) from early summer onwards. The sporophylls are intermingled with the sterile blades. E. menziesii may develop very long plants up to 8 m in length. Structure of sporophyte as in Laminaria composed of photosynthetic meristoderm, parenchymatic cortex and central medulla.

Life history diplohaplontic with alternation of large sporophyte bearing unilocular meiosporangia with paraphyses (sori) and microscopic dioecious and oogamous, heteromorphous gametophytes (for detail, see Laminaria). Haploid chromosome number is 8 (Myers 1925).

Information contributed by: I. Bartsch & M.D. Guiry. The most recent alteration to this page was made on 2014-06-21 by M.D. Guiry.

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

Most recent taxonomic treatment adopted: Silberfeld, T., Rousseau, F. & Reviers, B. de (2014). An updated classification of brown algae (Ochrophyta, Phaeophyceae). Cryptogamie Algologie 35(2): 117-156, 1 fig., 1 table.

Comments: The genus is endemic to the northeastern Pacific growing on rocks in the low intertidal and subtidal from British Columbia to Baja California.

The field distribution of E. menziesii is determined by a specific combination of high salinities and temperatures less than 15°C in British Columbia (Gordon & De Wreede 1978). The survival range of the sporophytes is -1.5-18°C (Léng and Freshwater 1988). The seawater force regime has significant effect on thallus strongness, stiffness, and work of fracture but not on toughness in juvenile E. menziesii sporophytes. These mechanical properties increase with high water speed independently from the alginic acid composition of the thalli (Kraemer & Chapman 1991).

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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=42098

Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 21 June 2014. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 22 November 2024