• Category
  • Length Range
    23.0-38.7 µm
  • Width Range
    6.9-9.2 µm
  • Striae in 10 µm



Valves are lanceolate with broadly rounded, protracted apices. The central area is transverse with marginal areolae and a single, distinct stigma positioned near the valve margin. Striae are radiate and increasingly so toward the apices. Areolae are coarse and easily visible in LM, measuring 16-18 in 10 µm at mid-valve, increasing to 20 µm at the apices. The axial area is narrow and linear, expanding slightly toward the central area. The raphe is filiform, with both proximal raphe ends deflected unilaterally, away from the isolated stigma.


Original Description

Valve broadly lanceolate with broadly rostrate ends, and axial area narrow, central area transverse. On one side of the central nodule a distinct stigma. Striae radiate throughout the valve. Strie, 16-19 in 10 µ at center of valve to 24 in 10 µ at ends of valve. Length, 21-36 µ (type, 36 µ). Breadth, 7-11 µ (type, 11 µ).

  • Basionym
    Navicula mutica var. stigma
  • Author
    R.M.Patrick 1959
  • Length Range
    21-36 µm
  • Width
    7-11 µm
  • Striae in 10µm
    16-19 at center; up to 24 at ends of valve

Original Images

Luticola Stigma Orig Desc Plate
Luticola Stigma Orig Desc Text

Cite This Page

Bishop, I. (2015). Luticola stigma. In Diatoms of North America. Retrieved May 20, 2024, from https://diatoms.org/species/luticola_stigma


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