• Category
  • Length Range
    21.0-35.2 µm
  • Width Range
    4.9-7.7 µm
  • Striae in 10 µm
    13-17 dorsal and 16-20 ventral at the valve center; 18-22 at the apices

Identification

Description

Valves are lanceolate with very narrow, weakly protracted apices. The dorsal margin is moderately arched; the ventral margin is somewhat less arched. The axial area gradually widens to merge with a slightly wider, but poorly defined central area. The raphe is lateral, becoming reverse-lateral at the proximal ends. Proximal raphe ends are deflected ventrally and terminate with very small central pores. Terminal raphe fissures are deflected dorsally. Striae are finely punctate and radiate. Areolae are distinct in LM. Isolated stigmata are absent.

Autecology

The specimens on this web page were collected from a mossy seep at the base of the Garden Wall along the Going-To-The-Sun Road in Glacier National Park, Montana.

Weepingwall
Credit: Becca Rapelje
Weeping Wall along the Going-To-The-Sun Road in Glacier National Park, Montana. A similar habitat nearby supported a large population of Cymbella laevis.

Original Description

  • Author
    Naegeli in Kütz. 1849

Original Images

Cymbella gracilis orig descr

Cite This Page

Bahls, L. (2016). Cymbella laevis. In Diatoms of North America. Retrieved July 21, 2018, from https://diatoms.org/species/cymbella_laevis

Responses

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