Valves are linear, with parallel sides and broadly rounded apices. The axial area is broad, up to 2/3 valve width, and widens to an elongated rhombic central area with a narrow asymmetric or symmetric transverse fascia. The raphe is lateral with question mark-shaped terminal fissures. Striae are radiate in the center becoming longer and convergent toward the ends. The central area contains four irregular markings, sometimes appearing like ghost striae. The four markings are variable and not always visible in LM.
These specimens are from Florida.
Aycock, L. (2022). Pinnularia lokana. In Diatoms of North America. Retrieved September 07, 2024, from https://diatoms.org/species/pinnularia-lokana
The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Pinnularia lokana 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.