• Category
  • Length Range
    11-16 µm
  • Width Range
    4.8-5.6 µm
  • Striae in 10 µm
    14-16 in the center of raphe valve, 15-17 in the center of raphe valve, up to 20 at the ends
  • Synonyms
    Achnanthes ploenensis var. gessneri (Hust.) Lange-Bert. in Lange-Bert. and Krammer

Identification

Description

Valves are elliptical-lanceolate with subrostrate to rostrate apices. Both raphe and rapheless valves have a narrow lanceolate axial area and lack a distinct central area. The raphe is straight. Striae on the raphe valve are strongly radiate, becoming parallel to slightly convergent toward the apices. The striae on the rapheless valve are slightly radiate, becoming parallel to slightly convergent toward the apices. The striae on the rapheless valve are interrupted by a marginal longitudinal line on each side of the valve.

Autecology

Original Description

Valvae elliptico-lanceolatae apicibus obtuse rostratis, 14-17 µ latae. Rhaphovalva rhaphe directa poris centralibus approximatis, area axiali anguste lanceolata, striis transapicalibus radiantibus in media parte circiter 16 in 10 µ, ad apices versus paulo densioribus, usque ad 20 in 10 µ. Areovalva area axiali anguste lanceolata, striis transapicalibus in media parte lenissime radiantibus vel ad lineam mediam perpendicularibus, 16-20 in 10 µ, ad apices versus magis radiantibus et paulo densioribus, prope marginem costa longitudinali decussatis. Fig. 14-19.

  • Basionym
    Achnanthes gessneri
  • Author
    Hust. 1953
  • Length Range
    14-17 µm
  • Width
    5-6 µm
  • Striae in 10µm
    16 in the center of raphe valve

Original Images

Achnanthes gessneri orig illus
Achnanthes gessneri orig descr

Cite This Page

Potapova, M. (2010). Karayevia ploenensis var. gessneri. In Diatoms of North America. Retrieved July 23, 2018, from https://diatoms.org/species/karayevia_ploenensis

Responses

The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Karayevia ploenensis var. gessneri 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.