• Category
  • Length Range
    12.5-21.7 µm
  • Width Range
    6.1-8.2 µm
  • Striae in 10 µm
    26-28 in the center valve, 28-30 at the ends



Valves are rhombic-elliptic, becoming elliptic in small valves, with broadly rounded ends. The axial area is narrow and linear. The central area is a distinctive “bow-tie” bordered by 5-8 irregularly shortened striae. Striae are curved and radiate throughout, and increase slightly in density toward the apices. The raphe is filiform, with straight proximal ends and distal ends deflected in opposite directions.


Cavinula lapidosa is widespread throughout the United States and Europe (Cantonati et al. 2017), but typically occurs in low abundance. Cavinula lapidosa is reportedly indicative of low nitrogen conditions (Potapova and Charles 2008) and silica-rich waters (Szczepocka and Rakowska 2007).

Original Description

Navicula lapidosa Krasske, nov. spec. Fig. 7.

Elliptisch bis stumpf rhomboid. Schmale lineare Längs-area, rechteckige Zentralarea, die fast bis an den Rand reicht, da die mittleren Streifen sehr verkürzt sind. Streifen 26 in 10 μ, strahlend, leicht gebogen, konvexe Seite den Schalenenden zu-gewandt. Länge 18 μ, Breite 8 μ.

Vorkommen: Nasse Granitwand am Bahneinschnitt am Milchhübel bei Oberputzkau (Lzb.).

  • Basionym
    Navicula lapidosa
  • Author
    Krasske 1929
  • Length Range
    18 µm
  • Width
    8 µm
  • Striae in 10µm

Original Images

Navicula Lapidosa Orig Illus
Navicula Lapidosa Orig Desc

Cite This Page

Polaskey, M. (2018). Cavinula lapidosa. In Diatoms of North America. Retrieved May 29, 2024, from https://diatoms.org/species/cavinula-lapidosa


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