• Category
  • Length Range
    11-18 µm
  • Width Range
    6.1-8.5 µm
  • Striae in 10 µm



Valves are elliptic-lanceolate with subrostrate apices. The raphe valve has a transversely rectangular to elliptic central area. The rapheless valve has a wide rhomboid axial area and asymmetric central area that contains a cavum on the internal valve surface. The raphe is straight with expanded external proximal ends. The multiseriate striae are radiate on both valves.


Original Description

Pseudoraphe valve with shortened striae forming a broad, lanceolate pseudoraphe. Other features as in the nominate variety. Length 11-26 µ. Breadth 6-8.5 µ. Striae 10-12 in 10 µ.

  • Basionym
    Achnanthes lanceolata var. abbreviata
  • Author
    Reimer 1966
  • Length Range
    11-26 µm
  • Width
    6-8.5 µm
  • Striae in 10µm

Original Images

Plabbrev  Or Ill001
Plabbrev  Or Descr001

Cite This Page

Potapova, M. (2011). Planothidium abbreviatum. In Diatoms of North America. Retrieved May 24, 2024, from https://diatoms.org/species/planothidium_abbreviatum


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