Diatoms of North AmericaDiatoms of North America

Stauroneis americana

Heiden in Schmidt et al. 1903

Stauroneis Americana Guide
  • Category
    Symmetric Biraphid
  • Length Range
    136-214 µm
  • Width Range
    32-46 µm
  • Striae in 10 µm
    11-14
  • Reported As
    Stauroneis javanica (Hustedt 1959)

Identification

Stauroneis americana LM6 Stauroneis americana LM5 Stauroneis americana LM4 Stauroneis americana LM3 Stauroneis americana LM2 Stauroneis americana LM1
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Description

Valves are broadly lanceolate with bluntly rounded apices. A prominent pseudoseptum is present at each apex. The axial area is broad and linear, about three times the width of the raphe. The central area is a rectangular stauros, about the same width as the axial area, widening very slightly near the valve margin. The raphe is lateral, becoming filiform near the central area. The proximal raphe ends are nearly straight and weakly expanded. Striae are slightly radiate throughout. Areolae are coarse and number 9-14 in 10 µm.

Autecology

Stauroneis americana is widely distributed in wetlands with alkaline pH and low to moderate conductivity, but it is rarely found in abundance. Van de Vijver et al. (2004) published a photo of a Stauroneis americana specimen from Yellowstone National Park (plate 91, fig. 2) and Lange-Bertalot & Genkal (1999) pictured a specimen from “the Rocky Mountains, North America” (Tafel 35, fig. 2).

Bloody Dick Pond 5 2
Credit: Loren Bahls
Bloody Dick Pond #5, Beaverhead County, Montana: Home of Stauroneis americana.

Original Description

  • Author
    Heiden in A.Schmidt et al. 1903

Original Images

Samer Orig

Cite This Page

Bahls, L. (2011). Stauroneis americana. In Diatoms of North America. Retrieved October 30, 2024, from https://diatoms.org/species/stauroneis_americana

Responses

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