• Category
  • Length Range
    26-43 µm
  • Width Range
    5.4-7.6 µm
  • Striae in 10 µm
    17-19 near the valve center, 19-21 near the ends
  • Reported As
    Encyonopsis montana (Bahls 2013, figs. 89, 90)
    Encyonopsis cesatii var. geitleri (Bahls 2012, Diatoms of the US)
    Encyonopsis montana (Bahls 2013, Diatoms of the US)



Valves are broadly lanceolate and nearly symmetric with respect to the apical axis. Apices are rostrate and deflected slightly to the ventral side. The axial area is narrow. The central area is small and asymmetric, rounded on the dorsal side and the ventral side with two or three shortened striae. The raphe is weakly lateral. Proximal raphe ends are deflected toward the dorsal side and distal raphe ends are hooked toward the ventral side. Striae are radiate throughout. Areolae are very fine and difficult to resolve in LM.


Encyonopsis cesatiformis was collected from a wetland and a small pond (pictured below) in Glacier National Park, Montana. The pH of the pond on the collection date was 7.78 and the specific conductance measured 139 µS/cm. Encyonopsis cesatiformis was described from material collected from a wetland in Finnish Lapland. It is also found in the European Alps. Krammer (1997) describes its preferred habitat as oligotrophic waters with low electrolyte content.

Kootenai  Pond And  Citadel  Peaks
Credit: Loren Bahls
Kootenai Pond, Glacier National Park, Montana: home of Encyonema vulgare

Original Description

  • Author
    Krammer 1997
  • Length Range
    26-49 µm
  • Width
    6.9-9.0 µm
  • Striae in 10µm

Original Images

Encyonopsis cesatiformis orig illus
Encyonopsis Cesatiformis Origdesc001

Cite This Page

Bahls, L. (2014). Encyonopsis cesatiformis. In Diatoms of North America. Retrieved May 29, 2024, from https://diatoms.org/species/encyonopsis_cesatiformis


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