• Category
  • Length Range
    12.7-25.5 µm
  • Width Range
    5.0-5.6 µm
  • Striae in 10 µm



Valves lanceolate with protracted apices ending rounded. Striae are radiate becoming parallel in the apices. Central area bow-tie shaped, bordered by shortened stria composed of usually one but sometimes two areolae. Stigma present in the central area, appearing round in LM. In SEM, the external stigma opening is transapically elongate and internally bordered by a closed "C"-shape siliceous structure. At the central area three marginal stria occur on the stigma side of the valve, with two marginal stria occurring opposite the stigma. Raphe is filiform, proximal ends deflect away from the stigma and the distal ends are hooked toward the stigma side of the valve. Stria are composed of round areolae, five to six per stria near the valve center, two to three per stria at the apices.


Here L. ignorata was sampled growing on riverine turtles of eastern Oklahoma, suggesting some ability to survive desiccation. Levkov et al. (2013) described this taxon from rivers of Brazil and assigned the epithet because the taxon was overlooked in monitoring data.

Original Description

Valves lanceolate to elliptical-lanceolate (in smaller specimens) with protracted and acutely rounded apices. Valve length 12-31 µm, valve width 5.0-7.5 µm. Axial area narrow, linear, slightly expanded towards central area. Central area wide, bow-tie-shaped. Central area on both valve margins bordered by 3 isolated round areolae. Single isolated, slit-like, transapically elongated stigma present in central area, located halfway between valve centre and margin. Raphe branches straight. Proximal raphe endings deflected to side opposite to stigma and expanded onto central pores. Distal raphe fissures hooked, first deflected towards same side as proximal endings and then hooked towards opposite side, continuing onto valve mantle, terminating shortly before valve edge. Transapical striae composed of 4-5 round to elongated areolae. Areolae externally covered with recessed cerebrum. Striae in LM punctate, radiate throughout, 18-20 in 10 µm.

  • Author
    Levkov, Metzeltin and A.Pavlov 2013
  • Length Range
    12-31 µm
  • Width
    5-7.5 µm
  • Striae in 10µm

Original Images

Luignorata Original Image
Luignorata Originaltext

Cite This Page

Burge, D., Wu, S., Edlund, M. (2017). Luticola ignorata. In Diatoms of North America. Retrieved July 19, 2024, from https://diatoms.org/species/luticola_ignorata


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