• Category
  • Length Range
    26.6-47.1 µm
  • Width Range
    7.2-9.6 µm
  • Striae in 10 µm
    16-19 at the valve center, 20-22 near the apices
  • Reported As
    Cymbella lapponica (Krammer and Lange-Bertalot 1986, p. 330, pl. 137, figs. 12-17)



Valves are weakly dorsiventral, rhombic-lanceolate, tapering gradually from the middle to narrow, subapiculate apices. The axial area is broad and follows the valve midline. The central area is asymmetric, with the dorsal side more developed. The raphe is weakly lateral, narrowing toward the proximal and distal ends. Proximal raphe ends are deflected slightly toward the ventral side. Terminal raphe fissures are comma shaped and deflected dorsally. Striae are radiate throughout. Areolae number 28-30 in 10 µm.


Cymbopleura lapponica has been collected in small numbers from six lakes, ponds, swamps and streams in the northern Rocky Mountains of Montana and Alberta. Here pH ranged from 7.78 to 8.04 and specific conductance varied from 129-183 µS/cm. Krammer (2003) reports this species from the subarctic (Spitsbergen), far northern Scandinavia, and the Alps. The type locality is in Swedish Lapland.

Bullhead  L   Swiftcurrent  Pass
Credit: Loren Bahls
Bullhead Lake, Glacier National Park, Montana: home of Cymbella alpestris

Original Description

  • Basionym
    Cymbella lapponica
  • Author
    Grunow in Cleve 1894

Cite This Page

Bahls, L. (2012). Cymbopleura lapponica. In Diatoms of North America. Retrieved June 21, 2024, from https://diatoms.org/species/cymbopleura_lapponica


The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Cymbopleura lapponica from all the stream reaches where it was present. Note that the relative abundance scale is the same on each plot. Explanation of each environmental variable and units are as follows:

ELEVATION = stream reach elevation (meters)
STRAHLER = distribution plot of the Strahler Stream Order
SLOPE = stream reach gradient (degrees)
W1_HALL = an index that is a measure of streamside (riparian) human activity that ranges from 0 - 10, with a value of 0 indicating of minimal disturbance to a value of 10 indicating severe disturbance.
PHSTVL = pH measured in a sealed syringe sample (pH units)
log_COND = log concentration of specific conductivity (µS/cm)
log_PTL = log concentration of total phosphorus (µg/L)
log_NO3 = log concentration of nitrate (µeq/L)
log_DOC = log concentration of dissolved organic carbon (mg/L)
log_SIO2 = log concentration of silicon (mg/L)
log_NA = log concentration of sodium (µeq/L)
log_HCO3 = log concentration of the bicarbonate ion (µeq/L)
EMBED = percent of the stream substrate that is embedded by sand and fine sediment
log_TURBIDITY = log of turbidity, a measure of cloudiness of water, in nephelometric turbidity units (NTU).
DISTOT = an index of total human disturbance in the watershed that ranges from 1 - 100, with a value of 0 indicating of minimal disturbance to a value of 100 indicating severe disturbance.