Polystrata Heydrich, 1905

Holotype species: Polystrata dura Heydrich

Original publication and holotype designation: Heydrich, F. (1905). Polystrata, eine Squamariacee aus den Tropen. Berichte der deutsche botanischen Gesellschaft 23: 30-36, Plate I.

Description: Thallus completely calcified, crustose and tightly adherent across the entire undersurface, composed of few to many layers of closely appressed blades. Individual blades consisting of a monostromatic uniaxial mesothallus of richly branched polyflabellate filaments that develop dorsal and ventral perithallial filaments from each of their cells’ upper and lower surfaces, respectively. Dorsal perithallus with or without cell fusions among the starch-filled lower cells. Ventral perithallus 1–many cells thick. Rhizoids absent. Large hair cells present or absent. Tetrasporangia decussate or cruciately divided, borne within gelatinous nemathecia of multicellular paraphyses. Gametophytes (where known) monoecious, developing male and female gametangia in the same or separate nemathecia. Carpogonial branches 3-celled and borne laterally on the basal cells of paraphyses. Auxiliary cell branches 4-celled; the suprabasal cell acting as the auxiliary cell, borne laterally on the basal cells of paraphyses. Gonimolobes developing either directly from the connecting filament or from a diploidised auxiliary cell. Carposporangia forming simple chains of 2 or 3. Spermatangia exhibiting the Peyssonnelia dubyi-type arrangement, forming dense tiered clusters around a central axis.

Information contributed by: K.R. Dixon (2018). The most recent alteration to this page was made on 2021-08-12 by M.D. Guiry.

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

Gender: This genus name is currently treated as feminine.

Most recent taxonomic treatment adopted: Dixon, K.R. (2018). Peyssonneliales. In: Algae of Australia. Marine benthic algae of north-western Australia. 2. Red algae. (Huisman, J.M. Eds), pp. 208-244. Canberra & Melbourne: ABRS & CSIRO Publishing.

Comments: Kylin (1956) treats Polystrata as a synonym of Peyssonnelia, but the genus is considered distinct by Denizot (1968). The type is from New Guinea, Indonesia, the Antilles, West Africa and the Mediterranean,and is only rarely recorded (Verlaque 1981). A second species also occurs in Indonesia, whereas the third is from the Mediterranean and Adriatic Seas. Polystrata alba (Pfender) Denizot is an Eocene fossil.

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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=34458

Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 12 August 2021. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 22 November 2024