• Category
  • Length Range
    46-87 µm
  • Width Range
    17.0-20.9 µm
  • Striae in 10 µm
    8-10 at the valve center, 12-14 near the apices
  • Reported As
    Cymbella lata (Moghadam 1969, p. 183)
    Cymbella lata (Patrick & Reimer 1975, p. 37, plate 5, fig. 4)



Valves are lanceolate to broadly elliptic-lanceolate and slightly to distinctly dorsiventral with broadly rostrate to apiculate apices. The axial area is uniformly rather narrow and merges with a somewhat wider ovoid central area that is a bit more developed on the dorsal side. The central area is nearly absent in smaller specimens. The raphe is lateral and becomes filiform at the ends. Proximal raphe ends are straight and inflated. Distal raphe ends are comma-shaped and deflected dorsally. Striae are radiate throughout and finely punctate. Areolae number 28-32 in 10 µm.


Cymbopleura lata is rare in the United States. It has been confirmed from two lakes and two rivers in northwest Montana and southwest Alberta and from Lake Metigoshe in northcentral North Dakota. The population shown here is from Lake Five in Flathead County, Montana. On the date this sample was collected, pH measured 8.90 and specific conductance measured 256 µS/cm. Moghadam (1969) reported C. lata from Blue Bay on the east side of Flathead Lake, Montana. A drawing of a Flathead Lake specimen is included in Patrick & Reimer (1975). Krammer (2003) reports C. lata var. americana from the Colorado River.

Lake  Five
Credit: Lake Five Resort
Lake Five, Flathead County, Montana: home of Cymbopleura lata.

Original Description

  • Basionym
    Cymbella lata
  • Author
    Grunow ex Cleve 1894

Original Images

Cymbella lata orig illus

Cite This Page

Bahls, L. (2012). Cymbopleura lata. In Diatoms of North America. Retrieved July 19, 2024, from https://diatoms.org/species/cymbopleura_lata


The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Cymbopleura lata 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.