Valves are linear-lanceolate, and only very slightly dorsiventral. The apices are rounded and slightly protracted. The raphe is lateral with sharply bent terminal fissures. The axial area is narrow and linear. The central area is formed by considerably a shortened stria on the ventral side and a very slightly shortened stria on dorsal side. Striae are parallel and mostly uniseriate, although occasionally some specimens are biseriate. Areolae are apically elongated, approximately 26 in 10 μm. Striae continue uninterrupted around the valve apices.
Encyonema appalachianum so far has been found in several rivers and reservoirs in western Pennsylvania. These water bodies were circumneutral to alkaline and had a wide range of water mineral content.
Potapova, M. (2014). Encyonema appalachianum. In Diatoms of North America. Retrieved October 30, 2024, from https://diatoms.org/species/encyonema_appalachianum
The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Encyonema appalachianum 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.