Spirirestis V.R.Flechtner & J.R.Johansen, 2002

Holotype species: Spirirestis rafaelensis V.R.Flechtner & J.R.Johansen

Original publication and holotype designation: Flechtner, V.R., Boyer, S.L., Johansen, J.R. & DeNoble, M.L. (2002). Spirirestis rafaelensis gen. et sp. nov. (Cyanophyceae), a new cyanobacterial genus from arid soils. Nova Hedwigia 74: 1-24.

Description: Colony softly mounded on agar, with slightly irregular margins, not tufted, dark blue-green, maintaining its colour at four months; the only evidence of colour change to olive or ochre occurring with cell death in drying, older cultures. Colony compact, with densely arranged filaments, but no evidence of external mucilage production. Although filaments can be seen within the colony at 30x magnification, filaments do not extend horizontally or vertically from the colony. Colony morphology is similar on both Bold's Basal and Z-8 media. Filaments forming tight, regular spirals which can be seen to taper slightly in young cultures. Filaments 6-20 um in diameter; spirals 16-28 urn in diameter at their widest point, tapered end of spirals about 75-80% of the maximum diameter; distance between regular spirals 8-12(-16) um. Some filaments more loosely coiled, or even extended; these filaments increasing in frequency in older cultures. Both single and double false branching occasionally observed in more loosely coiled or extended filaments, but not in tightly spiraled filaments. False branching usually distant from the heterocytes. Sheath firm, usually colourless, occasionally golden to brown, thin in young cultures becoming thicker and lamellated in older cultures, 1-4 µm thick. Trichomes not to slightly constricted at the crosswalls, more commonly constricted in older cultures and in loosely coiled or extended filaments, 5.5-14.0 µm in diameter.Cells mostly shorter than wide, occasionally quadratic, 2.0-7.2 µm long, without aerotopes, cell contents sometimes granular, especially in older cultures. Heterocytes both intercalary and basal within filaments, mostly single but occasionally double in intercalary position, rarely triple, spherical to oval, sometimes appressed on one side in basal position, light brown, 8-9 um in diameter, 4-9 µm long.

Information contributed by: V. Fletchner. The most recent alteration to this page was made on 2023-03-06 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: Strunecký, O., Ivanova, A.P. & Mares, J. (2022 '2023'). An updated classification of cyanobacterial orders and families based on phylogenomic and polyphasic analysis (Review). Journal of Phycology 59(1): 12-51.

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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=50675

Citing AlgaeBase
Cite this record as:
M.D. Guiry in Guiry, M.D. & Guiry, G.M. 06 March 2023. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. https://www.algaebase.org; searched on 19 April 2024