Taxon Account

Achnanthidium petersenii (Hustedt) C.E.Wetzel, Ector, D.M.Williams & Jüttner; 2019; 10

Key references

Jüttner I., Wetzel C.E., Williams D.M., Ector L. 2019. Investigations of the type materials of Achnanthes parallela J.R.Carter and Achnanthes petersenii Hustedt (Bacillariophyceae) with comments on the genus Rossithidium Round & Bukhtiyarova. Botany Letters DOI: 10.1080/23818107.2019.1668297.

Morphology

Size
11-18 µm long, 4-5 µm wide (Svalbard, type population).

Shape
Valves linear-lanceolate with slightly protracted broadly rounded apices.

Symmetry
Valves isopolar.

Valve
Frustules heterovalvate.

Striae
Striae slightly radiate throughout, 32-35 in 10 µm, on both valves.

Axial area
On raphe valve narrow, linear axial area, on rapheless valve moderately broad axial area, widening towards central area.

Central area
On raphe valve central area wide, rectangular or slightly acute-angled fascia, sometimes with very short striae at margin. On rapheless valve broad rhombic-lanceolate central area.

Raphe
Raphe slit straight with round or tear-drop-shaped proximal raphe ends and terminal raphe fissures.


SEM morphology
Uniseriate striae composed of 4-6 areolae, 1-3 areolae near apices.

Literature

References are given in chronological order.

Reference
Citation
Hustedt F. 1937. Süßwasserdiatomeen von Island, Spitzbergen und den Färöer-Inseln. Botanisches Archiv. 38: 152-207. Morphology; Description; Type Illustration; Taxonomy
Lange-Bertalot H., Krammer K. 1989. Achnanthes eine Monographie der Gattung mit Definition der Gattung Cocconeis und Nachträgen zu den Naviculaceae. Bibliotheca Diatomologica Vol. 18. 393 pp; 100 pls Morphology; Type Illustration; Taxonomy
Jüttner I., Wetzel C.E., Williams D.M., Ector L. 2019. Investigations of the type materials of Achnanthes parallela J.R.Carter and Achnanthes petersenii Hustedt (Bacillariophyceae) with comments on the genus Rossithidium Round & Bukhtiyarova. Botany Letters DOI: 10.1080/23818107.2019.1668297. Morphology; Taxonomy; Type Illustration;
This page should be cited as:

Wetzel C. E., Ector L., Williams D. M., Jüttner I. Achnanthidium petersenii (Hustedt) C.E.Wetzel, Ector, D.M.Williams & Jüttner; 2019; 10. In: Jüttner I., Bennion H., Carter C., Cox E.J., Ector L., Flower R., Jones V., Kelly M.G., Mann D.G., Sayer C., Turner J. A., 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=4629. [Accessed:  ].
Record last modified: 27/12/2020