Taxon Account

Navicula cryptocephala Kützing; 1844; 95

Key references

Cox E.J. 1995. Studies on the diatom genus Navicula Bory. VII. The identity and typification of Navicula gregaria Donkin, N. cryptocephala and related taxa. Diatom Research. 10(1): 91-111.

Morphology

Size
25.0-34.1 µm long, 5.8-6.7 µm wide (UK population), 20-40 µm long, 5-7 µm wide (Lange-Bertalot 2001).

Shape
Lanceolate with rostrate or subcapitate apices.

Symmetry
Isopolar, bilaterally symmetrical.

Striae
Radiate striae, slightly convergent at the valve ends; 14-17 in 10 µm (lectotype, Cox 1995).

Axial area
Narrow linear.

Central area
Rounded, slightly wider than long, sometimes slightly asymmetrical, approximately half the valve width.

Raphe
The raphe lies in a slightly thickened axial rib; central endings widely separated and expanded, terminal endings clearly and strongly hooked towards the secondary side of the valve.

Other features
Two plate-like chloroplasts symmetrically positioned and extending almost to the apices.

Literature

References are given in chronological order.

Reference
Citation
Kützing F.T. 1844. Die Kieselschaligen Bacillarien oder Diatomeen. Fr. Fritsch, Nordhausen. 152 pp; 30 pls Description; Morphology; Illustrations
Cox E.J. 1995. Studies on the diatom genus Navicula Bory. VII. The identity and typification of Navicula gregaria Donkin, N. cryptocephala and related taxa. Diatom Research. 10(1): 91-111. Morphology; Taxonomy; Type Illustration;
Lange-Bertalot H. 2001. Navicula sensu stricto, 10 genera seperated from Navicula sensu lato, Frustulia. 2. Lange-Bertalot H. (ed.), Diatoms of Europe, Diatoms of the European Inland waters and comparable habitats. A.R.G. Gantner Verlag K.G., Ruggell. 526 pp Morphology; Illustrations; Ecology
Poulíčková A., Neustupa J., Hašler P., Tomanec O., Cox E.J. 2016. A new species, Navicula lothargeitleri sp. nov., within the Navicula cryptocephala complex (Bacillariophyceae). Phytotaxa. 273(1): 23-33. Morphology; Illustrations
Jüttner I., Chudaev D., Kusber W.-H. 2020. Re-examination of the type materials of Navicula exilis and Navicula cryptocephala (Naviculaceae, Bacillariophyceae). Phytotaxa. 472(2): 123-134.
This page should be cited as:

Cox E. J., Jüttner I. Navicula cryptocephala Kützing; 1844; 95. 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=2574. [Accessed:  ].

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Record last modified: 27/12/2020