Taxon Account

Achnanthidium caledonicum (Lange-Bertalot) Lange-Bertalot; 1999; 277


Achnanthes caledonica Lange-Bertalot in Lange-Bertalot & Moser 1994
Achnanthes scotica (Carter) Lange-Bertalot 1993
Achnanthes minutissima var. scotica (Carter) Lange-Bertalot in Lange-Bertalot & Krammer 1989
Achnanthidium minutissimum var. scoticum (Carter) H.Cremer in H. Cremer & B. Wagner 2003
Achnanthes microcephala f. scotica Carter & Bailey-Watts 1981

Key references

Carter J. R., Bailey-Watts A. E. 1981. A taxonomic study of diatoms from standing freshwaters in Shetland. Nova Hedwigia. 33: 513-630.


28.8-33.1 µm long, 3 µm wide (UK population).

Valves linear with broad subcapitate to capitate ends. Frustules in girdle view bent with reflexed ends.

Valves isopolar.

Frustules heterovalvar with concave raphe valve and convex rapheless valve.

Slightly radiate near the valve centre, becoming more radiate close to the poles.

Axial area
Linear, slightly widening towards the valve centre on the raphe and rapheless valve.

Central area
Rounded with shortened and wider spaced, marginal striae or a transverse fascia on the raphe valve; oval or lanceolate with shortened, wider spaced striae, or a transverse fascia on the rapheless valve. On both valves the transverse fascia can be present only on one side with 1 or 2 shortened striae present on the opposite side.

Simple, filiform with straight, hardly expanded proximal and distal ends.


References are given in chronological order.

Carter J. R., Bailey-Watts A. E. 1981. A taxonomic study of diatoms from standing freshwaters in Shetland. Nova Hedwigia. 33: 513-630. Morphology; Taxonomy; Description; Type Illustration;
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; Taxonomy
Lange-Bertalot H. 1993. 85 Neue Taxa und über 100 weitere neu definierte Taxa ergänzend zur Süßwasserflora von Mitteleuropa Vol. 2/1-4. Bibliotheca Diatomologica 27, J. Cramer, Berlin, Stuttgart. 454 pp Taxonomy
Lange-Bertalot H., Moser G. 1994. Brachysira. Monographie der Gattung. 29. J. Cramer, Berlin. 212 pp Taxonomy
Williams D. M., Reid G. 2002. The diatom type slides and bibliography of John Carter (1908-1993). Bull. nat. Hist. Mus. Lond. (Bot.). 32(2): 137-151. Taxonomy
Cremer H., Wagner B. 2003. The diatom flora in the ultra-oligotrophic Lake El’gygytgyn, Chukotka. Polar Biology. 26: 105-114. Taxonomy
Krammer K., Lange-Bertalot H. 2004. Süßwasserflora Mitteleuropas. Bacillariophyceae. 4. Teil. Achnanthaceae. Kritische Ergänzungen zu Achnanthes s.l., Navicula s.str., Gomphonema. Eds Ettl H., Gärtner G., Heynig H., Mollenhauer D., Gustav Fischer Verlag, Stuttgart. 468 pp Illustrations
Slate J.E., Stevenson R.J. 2007. The diatom flora of phosphorus-enriched and unenriched sites in an Everglades marsh. Diatom Research. 22(2): 355-386. Morphology; Illustrations
Wojtal A.Z., Ector L., Van de Vijver B., Morales E.A., Blanco S., Piatek J., Smieja A. 2011. The Achnanthidium minutissimum complex (Bacillariophyceae) in southern Poland. Algological Studies. 136/137: 167-191. Morphology; Illustrations
Blanco S. 2016. A nomenclatural note on two species of the Achnanthidiaceae (Bacillariophyta). Notulae algarum. 4: 1-2. Taxonomy

Similar Species

Similar species not published on this website:

Achnanthidium duthii (Sreenivasa) Edlund; 1994

Achnanthidium mangelsdorffii Metzeltin & Lange-Bertalot; 2007; 24

This page should be cited as:

Jüttner I. Achnanthidium caledonicum (Lange-Bertalot) Lange-Bertalot; 1999; 277. In: Jüttner I., Carter C., Chudaev D., 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 [Accessed:  ].

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Record last modified: 27/12/2020