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Cymbella alpestris

Krammer 2002      Category: Asymmetrical biraphid

REPORTED AS: Cymbella cymbiformis var. nonpunctata (Patrick & Reimer 1975, p. 55, pl. 10, fig. 5) 

Cymbella affinis


Cymbella amplificata

LM scalebar = 10 µm = 80 pixels.


Contributor: Loren Bahls - May 2016
Length Range: 40-65 µm
Width Range: 9.0-11.7 µm
Striae in 10 µm: 8-10 at the valve center, up to 12 at the apices


Valves are dorsiventral with rounded ends that may be weakly protracted and upturned in some specimens. Dorsal margin is strongly arched; ventral margin is weakly concave with a tumid center. The axial area is about 1/4th the valve width and merges with a somewhat wider elliptic central area. The raphe is distinctly lateral, becoming reverse-lateral near the proximal ends and filiform near the terminal ends. Proximal raphe ends are deflected ventrally and tipped with weakly inflated pores. Distal raphe ends are deflected dorsally at a 45 degree angle and do not bisect the terminal pore fields. Striae are radiate, becoming more strongly radiate near the valve apices. Striae are distinctly punctate with areolae that number 20-25 in 10 µm. Isolated stigmata are absent.

Krammer (2002) considers this taxon to be synonomous with C. cymbiformis var. nonpunctata Fontell sensu Reimer in Patrick & Reimer (1975).

Original Description

Author: Krammer 2002
Length Range: 39-70 µm
Width Range: 9.7-12.1 µm
Striae in 10 µm: 6-8(9) dorsal and 8-9 ventral at the valve center, up to 12 near the ends

Original Description

Original Images

Cite This Page:
Bahls, L. (2016). Cymbella alpestris. In Diatoms of the United States. Retrieved May 24, 2018, from

Species: Cymbella alpestris

Contributor: Loren Bahls

Reviewer: Rex Lowe


Krammer, K. (2002). The genus Cymbella. Diatoms of Europe. Diatoms of the European Inland Waters and Comparable Habitats 3: 1-584.

Patrick, R.M. and Reimer, C.W. (1975). The Diatoms of the United States, exclusive of Alaska and Hawaii, V. 2. Monographs of the Academy of Natural Sciences of Philadelphia 13.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Cymbella alpestris CAS

North American Diatom Ecological Database (NADED)


Autecology Discussion

Cymbella alpestris has been recorded from several springs, lakes and wetlands in northern Montana and North Dakota. All of these sites have experienced glaciation in the past, either by mountain or continental glaciers. By contrast, C. hantzschiana may be found in both glaciated and unglaciated regions. Besides cool temperatures, the waters that support C. alpestris are all alkaline, with pH values ranging from 8.04 to 9.60. This species can tolerate a wide range of electrical conductivity, with measured values ranging from 129 µS/cm in Bullhead Lake, Glacier National Park (photo below) to 1693 µS/cm in a kettle lake in North Dakota on the Northwest Glaciated Plains. Cymbella alpestris was described from a population in the Swiss Alps and has also been reported from Scandinavia.


Bullhead Lake, Glacier National Park, Montana: home of Cymbella alpestris

Credit/Source: Loren Bahls