• Category
  • Length Range
    30-60 µm
  • Width Range
    9–12 µm
  • Striae in 10 µm



Valves are lanceolate, with rounded ends, 9-12 µm wide, 30-60 µm long. The raphe is filiform, with the central portions of the branches and central raphe endings slightly deflected towards the primary side of the valve. Terminal raphe fissures are hooked towards the secondary side. The axial area is narrow, linear. The central area is rounded rectangular or square. Striae are radiate, but convergent at the valve apices, 10-13 in 10 µm. Areolae ~32 in 10 µm.


Fresh and brackish water. Eutraphentic, cold-water species.

Original Description

Frustulia lanceolata, strato luteo-fusco submucoso e frustulis lanceolatis angustis obtusiusculis uniformiter coloratis constituto. In ostio thermarum ad Carlsbad, demersa ubi aqua adhuc calida (25 R.)

  • Basionym
    Frustulia lanceolata
  • Author
    C.Agardh 1827

Original Images

Nalanceol  Orig Descr

EMAP Assessment

EMAP Distribution

N Lanceolata 20
Map 20

Response Plots

Navicula Lanceolata

Cite This Page

Potapova, M. (2009). Navicula lanceolata. In Diatoms of North America. Retrieved June 20, 2018, from https://diatoms.org/species/navicula_lanceolata


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