Karayevia ploenensis var. gessneri (Hustedt) Bukhtiyarova; 1999; 148
Synonymy
Achnanthes ploenensis var. gessneri (Hustedt) Lange-Bertalot
Achnanthes gessneri Hustedt
Key references
Hustedt F. 1953. Diatomeen aus der Oase Gafsa in Südtunesien, ein Beitrag zur Kenntnis der Vegetation afrikanischer Oasen. Archiv für Hydrobiologie . 48: 145-153.
Morphology
Shape
Valves linear-elliptic with broadly rounded subrostrate ends.
Symmetry
Isopolar, bilaterally symmetrical, heterovalvar.
Striae
Coarse striae on both valves, radiate on the raphe valve becoming slightly radiate at the valve ends; slightly radiate on the rapheless valve and interrupted near the margin by a narrow plain longitudinal band. the straie appear smooth and structureless in LM
Axial area
Narrow on the raphe valve, though widening towards the centre; wider and linear lanceolate on the rapheless valve.
Central area
Not distinct from the axial areas on both valves.
Raphe
Straight; raphe ending morphology scarcely visible in LM.
SEM morphology
External proximal raphe endings slightly expanded, straight or deflected to the same side; distal raphe endings forming a question mark and terminating at the valve face/mantle junction.
Striae on the raphe valve consist of transapically elongate, large and wide grooves which are occluded by hymenes. On the rapheless valve there are narrower and shorter grooves on the valve face and a hyaline area near the junction of valve face and mantle separates these grooves from much shorter openings along the valve mantle.
Valves linear-elliptic with broadly rounded subrostrate ends.
Symmetry
Isopolar, bilaterally symmetrical, heterovalvar.
Striae
Coarse striae on both valves, radiate on the raphe valve becoming slightly radiate at the valve ends; slightly radiate on the rapheless valve and interrupted near the margin by a narrow plain longitudinal band. the straie appear smooth and structureless in LM
Axial area
Narrow on the raphe valve, though widening towards the centre; wider and linear lanceolate on the rapheless valve.
Central area
Not distinct from the axial areas on both valves.
Raphe
Straight; raphe ending morphology scarcely visible in LM.
SEM morphology
External proximal raphe endings slightly expanded, straight or deflected to the same side; distal raphe endings forming a question mark and terminating at the valve face/mantle junction.
Striae on the raphe valve consist of transapically elongate, large and wide grooves which are occluded by hymenes. On the rapheless valve there are narrower and shorter grooves on the valve face and a hyaline area near the junction of valve face and mantle separates these grooves from much shorter openings along the valve mantle.
Literature
References are given in chronological order.
Reference |
Citation |
|---|---|
| Hustedt F. 1953. Diatomeen aus der Oase Gafsa in Südtunesien, ein Beitrag zur Kenntnis der Vegetation afrikanischer Oasen. Archiv für Hydrobiologie . 48: 145-153. | Description; Illustrations; Morphology; Taxonomy; |
| Bukhtiyarova, L. 1999. Diatoms of Ukraine inland waters. National Academy of Sciences of Ukraine, M.G. Kholodny Institute of Botany, Kyiv, Ukraine. 133 pp.. | Taxonomy |
This page should be cited as:
Jüttner I., Mann D. G. Karayevia ploenensis var. gessneri (Hustedt) Bukhtiyarova; 1999; 148. In: Jüttner I., Carter C., Cox E.J., Ector L., Jones V., Kelly M.G., Kennedy B., Mann D.G., Turner J. A., Van de Vijver B., Wetzel C.E., Williams D.M..
Freshwater Diatom Flora of Britain and Ireland. Amgueddfa Cymru - National Museum Wales. Available online at https://naturalhistory.museumwales.ac.uk/diatoms/browsespecies.php?-recid=2458. [Accessed:
].
Image Gallery
Record last modified: 27/12/2020