• Category
  • Length Range
    29.2-41.2 µm
  • Width Range
    12.9-16.8 µm
  • Striae in 10 µm



Valves are expanded and elliptic, tapering sharply to apiculate apices. The axial area is narrow and linear. The central area is transversely elliptic. In some specimens, ghost striae or scattered areolae are present in the central area. Striae are distinctly punctate and parallel at the center of the valve, becoming slightly radiate at the apices. The proximal raphe ends are characteristically deflected into small, but distinguishable hooks that are deflected in opposite directions from one another. Relatively large longitudinal canals border the valve margin.


Neidium pseudodensestriatum prefers slightly acidic freshwater lakes, and tends to occur with Frustulia and Brachysira throughout the northeast U.S. and Florida (Stachura-Suchoples et al. 2004). The images presented here are of specimen from lake sediments of New Hampshire and New Jersey.

Original Description

Neidium pseudodensestriatum Stachura-Suchoples & Kociolek, sp. nov. (Figs 1-23)

Description: Valves elliptical-lanceolate to elliptical, with apices acute to rounded, length 18-52 μm, breadth 10.5-17 μm. Striae straight, 21-26/10 μm, parallel to slightly radiate except at the apices where they are slightly arched and parallel. Axial area straight, narrow. Central area rectangular. External proximal raphe ends deflected in opposite directions. Longitudinal canals marginal. Distal raphe ends appear forked.

Holotype: CAS slide 539047

Isotypes: The Natural History Museum, London (BM 101034); Canadian Museum of Nature, Ottawa (CANA 76138)

Type material: Cleaned sediment, CAS 620642, collector P. A. Siver, March 2000.

Type locality: Wildcat Lake, Ocala National Forest, Florida, U.S.A. (N 29°10’13’’; W 81°37’34’’). It grows as an epiphyte on aquatic plants.

  • Author
    Stachura-Suchoples and Kociolek 2004
  • Length Range
    18-52 µm
  • Width
    10.5-17 µm
  • Striae in 10µm

Original Images

Neidium Pseudodensestriatum Orig Illus
Neidium Pseudodensestriatum Orig Desc

Cite This Page

Polaskey, M., Camp, A. (2018). Neidium pseudodensestriatum. In Diatoms of North America. Retrieved July 19, 2024, from https://diatoms.org/species/neidium-pseudodensestriatum


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