Taxon Account

Achnanthidium crassum (Hustedt) Potapova & Ponader; 2004; 38

Key references

Potapova M.G., Ponader K.C. 2004. Two common North American diatoms Achnanthidium rivulare sp. nov. and A. deflexum (Reimer) Kingston: morphology, ecology and comparison with related species. Diatom Research. 19(1): 33-57.

Morphology

Size
6.5-19 µm long, 3-4 µm wide (UK population), 7.3-19.6 µm long, 3.0-4.5 µm wide (type from Sumatra, Potapova & Ponader 2004).

Shape
Valves linear-elliptic to elliptic with rounded poles.

Symmetry
Valves isopolar, bilaterally symmetrical.

Striae
Slightly radiate, in valve centre striae can be more or less parallel, in particular on the rapheless valve; central striae on raphe valve wider spaced; 19-23 in 10 µm.

Axial area
Narrow linear, slightly widening towards valve centre.

Central area
Small rounded on raphe valve, indistinct on rapheless valve.

Raphe
Straight with small teardrop-shaped proximal raphe ends and terminal fissures hooked towards the same side.


SEM morphology
External areola openings round, sometimes adjacent areolae merge, internally areolae occluded by cribra.

Literature

References are given in chronological order.

Reference
Citation
Hustedt F. 1938. Systematische und ökologische Untersuchungen über die Diatomeen-Flora von Java, Bali und Sumatra nach dem Material der Deutschen limnologischen Sunda-Expedition. Teil 1. 15. Archiv für Hydrobiologie, Supplement. 131-506 pp Description; Illustrations
Potapova M.G., Ponader K.C. 2004. Two common North American diatoms Achnanthidium rivulare sp. nov. and A. deflexum (Reimer) Kingston: morphology, ecology and comparison with related species. Diatom Research. 19(1): 33-57. Morphology; Type Illustration; Taxonomy
Jüttner I., Chimonides P.D.J., Ormerod S.J., Cox E.J. 2010. Ecology and biogeography of Himalayan diatoms: distribution along gradients of altitude, stream habitat and water chemistry. Fundamental and Applied Limnology. 177(4): 293-311. Ecology
Jüttner I., Chimonides J., Cox E.J. 2011. Morphology, ecology and biogeography of diatom species related to Achnanthidium pyrenaicum (Hustedt) Kobayasi (Bacillariophyceae) in streams of the Indian and Nepalese Himalaya. Algological Studies. 136: 45-76. Ecology; Illustrations

Similar Species

Similar species not published on this website:

Achnanthidium delmontii Pérès, Le Cohu & Barthès; 2012; 190

Achnanthidium rivulare Potapova & Ponader; 2004; 36

This page should be cited as:

Jüttner I., Ector L. Achnanthidium crassum (Hustedt) Potapova & Ponader; 2004; 38. 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=3660. [Accessed:  ].

Image Gallery

Record last modified: 27/12/2020