• Category
  • Length Range
    17-33 µm
  • Width Range
    4.7-6.3 µm
  • Striae in 10 µm



Valves are narrowly lanceolate with unprotracted and acutely rounded apices. Raphe branches are filiform with proximal ends deflected slightly to the primary side. Distal raphe fissures are hooked to the secondary side. The axial area is very narrow. The central area is small, elliptic, and asymmetric, and bordered by 1-4 shortened striae. Striae are weakly radiate, becoming convergent toward the apices. Areolae number about 32 in 10 μm and are usually visible in LM.


Navicula staffordiae is known only from Sand Creek, Garfield County, Montana. The following water quality variables were measured at this location on the sampling date: pH 8.85, specific conductance 1756 μS/cm, total phosphorus 0.447 mg/L, orthophosphate 0.010 mg/L, total nitrogen 3.037 mg/L, dissolved oxygen 6.57 mg/L, temperature 21.8 °C.

Original Description

Valves are narrowly lanceolate with acutely rounded ends, 17–33 μm long, 4.7– 6.3 μm wide. Raphe filiform, proximal endings defl ected to the primary side, distal raphe fissures hooked to the secondary side. Axial area very narrow, central area small and asymmetric. Striae radiate, abruptly becoming convergent toward the ends, 14 –16 in 10 μm, lineolae about 32 in 10 μm, visible in LM. For measurements, n = 32 valves. SEM (Figs 26 – 28): External raphe fissures filiform, proximal endings deflected slightly to the primary side. Distal raphe endings hooked, the hooks opening toward the secondary side (the side with the Voigt faults). Other features unremarkable.

  • Author
    Bahls 2012
  • Length Range
    17-33 µm
  • Width
    4.7-6.3 µm
  • Striae in 10µm

Original Images

Nstaffordiae Origimag1
Nstaffordiae Origimag2
Nstaffordiae Origidesc

Cite This Page

Bahls, L. (2012). Navicula staffordiae. In Diatoms of North America. Retrieved May 24, 2024, from https://diatoms.org/species/navicula_staffordiae


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