• Category
  • Length Range
    10-26 µm
  • Width Range
    3.5-4 µm
  • Striae in 10 µm



Valves are lanceolate in larger specimens to elliptical in smaller specimens, 3.5-4 µm wide by 8-26 µm long. Valves have rostrate ends in larger specimens to rounded ends in smaller specimens. The valve face is flat and the transition between the valve face and the mantle is gradual. The axial area is widely lanceolate. In girdle view, frustules are rectangular, joined by linking spines. Colonies may be planktonic or attached to the substratum at one end by a frustule with a mucilage pad. Striae are short, distinct, extending onto the mantle, composed of wide, round to oval areolae, 12-15 in 10 µm, parallel to radiate in the central of the valve to slightly radiate toward the valve ends. Costae are broad. Spines are spatulate, solid, some with terminal digitations that attach to the neighboring valve lineolae. Spines are present along the valve face edge, except at the apices, and always located on striae. Apical pore fields with round poroids are present on the valve mantle close to valve face. Copulae (girdle bands) are open and lack perforations.

US collected samples show a wide range of morphological variants sometimes mixed in material from a single locality. The origin of these variants is uncertain as is their taxonomic affinity. Here we follow the interpretation of Patrick and Reimer (1966) and present populations that resemble the iconotype of Van Heurck (1885).

Original Description

Valve lancéolée à extrémités diminuées-rostrées; stries très-courtes et marginales, au nombre de 13 à 14 en 1 c.d.m. Longueur 1 ¼ à 2 c.d.m. Eaux douces. - Bruxelles (Delogne).

  • Basionym
    Fragilaria brevistriata
  • Author
    Grunow in Van Heurck 1885

Original Images

Original Description

Cite This Page

Morales, E. (2010). Pseudostaurosira brevistriata. In Diatoms of North America. Retrieved June 21, 2024, from https://diatoms.org/species/pseudostaurosira_brevistriata


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