• Category
  • Length Range
    22-32 µm
  • Width Range
    4.5-5.2 µm
  • Striae in 10 µm
    14-22 in the center valve, 28-34 at the ends
  • Synonyms
    Achnanthes duthiei Sreen.
    Rossithidium duthiei ('duthii') (Sreen.) Kingston



Valves are linear to linear-lanceolate, with broadly capitate ends. The raphe valve is concave and the rapheless valve is convex. Both valves possess a linear axial area, which widens slightly in the middle portion of the valve. No central area is present. The striae are parallel or very slightly radiate throughout both valves. Striae density on both valves is 14-22 in 10 µm in the middle and 28-34 in 10 µm at the apices. The external openings of the areolae are transapically elongated, appearing as narrow slits. Each stria in the middle part of the valve is composed of 4-5 areolae. The raphe is straight, filiform. The terminal raphe fissures are hooked towards the same side of the valve. Externally, the central raphe ends are teardrop-shaped. Internally, the central raphe ends curve to opposite sides.


Original Description

  • Basionym
    Achnanthes duthei
  • Author
    Sreen. 1971
  • Length Range
    20-33 µm
  • Width
    4-4.5 µm
  • Striae in 10µm

Original Images

Achnanthes duthei orig illus
Achnanthes duthei orig illus 2
Achnanthidium duthei orig descr

Cite This Page

Potapova, M. (2010). Achnanthidium duthiei. In Diatoms of North America. Retrieved June 23, 2024, from https://diatoms.org/species/achnanthidium_duthii


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