• Category
  • Length Range
    20.6-36.0 µm
  • Width Range
    5.6-8.3 µm
  • Striae in 10 µm
    8-11 dorsal; 11-13 ventral
  • Reported As
    Encyonema droseraphilum (Bahls et al. 2013, p. 36, figs 3-10)



Valves dorsiventral with narrowly rounded apices. Dorsal valve margin convex; ventral valve margin nearly flat and slightly tumid in the center. Length to width ratio 2.8–5.7. Axial area very narrow and confluent with a slightly wider central area. Proximal raphe ends are slightly inflated and deflected dorsally. Distal raphe ends are curved towards the ventral margin. Dorsal striae are radiate. A single indistinct stigmoid lies at the proximal end of the middle dorsal stria. Ventral striae are much shorter and parallel near the valve center, becoming convergent towards the apices. Areolae number 28–32 in 10 μm.

This species was described as E. droseraphilum in 2013 by Bahls et al., who were not aware that it had already been described and named by Krammer in 1997.


Encyonema procerum has been collected from a floating mat fen and a shallow lake in the forested mountains of northwestern Montana (photos below). Both localities are rich in aquatic vegetation. On the date of collection, pH in the fen measured 6.77 and specific conductance measured 257 µS/cm.

Mud  Lake  Bob  Marshall  Wilderness 1
Credit: John Pierce
Mud Lake, Bob Marshall Wilderness, Flathead National Forest, Montana.
Drosera  Pond
Credit: Loren Bahls
Drosera Pond at Indian Meadows Research Natural Area, Helena National Forest, Montana.

Original Description

  • Basionym
    Encyonema procerum
  • Author
    Krammer 1997
  • Length Range
    18-40 µm
  • Width
    6.1-7.3 µm
  • Striae in 10µm

Original Images

Encyonema Procerum Origimag001
Encyonema Procerum Origdesc001

Cite This Page

Bahls, L. (2016). Encyonema procerum. In Diatoms of North America. Retrieved June 23, 2024, from https://diatoms.org/species/encyonema_procerum


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