• Category
  • Length Range
    33-44 µm
  • Width Range
    14-16 µm
  • Striae in 10 µm



Valves are elliptic to linear-elliptic with rounded ends. The axial area is narrow, linear to lanceolate, expanding toward a round central area, 3.3–3.8 µm wide. The longitudinal canal is linear, expanded in the middle of the valve with three to four rows of areolae narrowing into two near the valve apices. The raphe is straight with slightly expanded central ends and shortly curved distal ends. The striae are radiate with one row of coarse, round areolae numbering 13–15 in 10 μm.


The specimens displayed here were found in lake sediments of the northeast, within Crosby Pond, Maine.

The species was described from material collected from Lake Iowa, Iowa in the late 19th century and archived in the Krasske Collection (Lange-Bertalot et al. 2020).

Original Description

Valves elliptic to oblong-elliptic but falling short of becoming linear-elliptical. Ends broadly rounded. Length 24–46 μm, breadth 12–16 μm; ratio length-to- breadth 2–2.9. Raphe filiform, sometimes taking on an oblique appearance due to the internal parallel depressions. Axial area rarely linear, mostly somewhat expanded towards the centre, 1–2 μm wide. Central area 2–4 μm wide, i.e. ca. 1/4 of the valve width. Shape of the canal system narrowly lanceolate, more or less arcuate around the central nodule, marked there by 3–4, distally by two canal areolae. All striae radiate and evenly spaced, 13–14 in 10 μm, appearing uniseriate throughout. Areolae 13.5–15 in 10 μm.

  • Author
    Lange-Bert. and Fuhrmann 2020
  • Length Range
    24–46 µm
  • Width
    12–16 µm
  • Striae in 10µm

Original Images

Diploneis doncharlesii Orig Illus
Diploneis doncharlesii Orig Desc

Cite This Page

Jovanovska, E. (2021). Diploneis doncharlesii. In Diatoms of North America. Retrieved May 24, 2024, from https://diatoms.org/species/diploneis-doncharlesii


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