Valves are linear-lanceolate. Axial area is narrow. Central area is strongly asymmetrical, wedge-shaped and bordered by irregularly shortened striae at the primary side and semi-lunate in shape on the secondary side. Raphe is almost straight, but slightly shifted towards primary side near the central valve. Proximal raphe ends are slightly expanded and sharply deflected towards the primary side. Terminal raphe fissures are deflected toward the primary side and bifurcate at the valve apices. Striae are radiate in the central part of the valve and parallel near apices. Striae are 9-10 in 10 µm. Areolae are lineolate and number approximately 24-26 in 10 µm.


Original Description

Valves linear-lanceolate, 46-50 µm long, 8-9 µm wide. Raphe almost straight, but near the center slightly bent towards primary side of the valve. Central raphe endings slightly expanded and sharply bent towards primary side. Terminal fissures deflected towards primary side and bifurcate over valve apices. Striae radiate at the middle part of the valve, but parallel near apices, 9-10 in 10 µm. Areolae apically elongate, about 24-26 in 10 µm. Axial area narrow. Central area asymmetrical, bordered by irregularly shortened striae at the primary side, and semi-lunate at the secondary side.

  • Author
    Potapova in Potapova and Charles 2004
  • Length Range
    46-50 µm
  • Width
    8-9 µm
  • Striae in 10µm

Original Images

Nageronim  Or Ill
Nageronim  Or Descr

Cite This Page

Potapova, M. (2011). Navicula geronimensis. In Diatoms of North America. Retrieved August 15, 2018, from


The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Navicula geronimensis 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)
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_SIO2 = log concentration of silicon (mg/L)
log_NA = log concentration of sodium (µeq/L)