• Category
  • Length Range
    9-23 µm
  • Width Range
    4.8-7.5 µm
  • Striae in 10 µm
  • Synonyms
    Psammothidium grischunum f. daonensis (Lange-Bert.) Bukht. and Round



Valves are elliptical to linear-elliptical. The raphe valve has a linear axial area, which widens into a transapically elliptical, rectangular, or diamond-shaped central area. The raphe is straight, without terminal fissures. The central and terminal raphe ends are slightly expanded externally. The central raphe ends curve toward opposite sides internally. The rapheless valve has a large rhomboid axial area, which has an irregular border. The central area is usually not differentiated from the axial area. Striae are radiate on both valves, 24-30 in 10 µm, interrupted at the valve margin. One row of areolae is present on the mantle of both valves; occasionally a second row of areolae is inserted on the valve margin. Areolae are 36-48 in 10 µm within the striae. The external openings of the areolae are mostly circular, occasionally elongated.


Original Description

Valvae ellipticae ad lineari-ellipticae apicibus late rotundatis non protractis, 10-26 μm longae, 5-8 μm latae. Raphovalva: Raphe filiformis recta, poros terminales influens; pori centrales modice approximate. Area axialis anguste linearis area centralis variabiliter transverse dilatata. Areovalva: Area axialis plus minusque late lanceolata influens in aream centralis rhombicam irregulariter marginatum. Striae transapicales modice radiantes in media parte valvarum usque ad apices, 27-32/10 μm. Quamquam similis a A. marginulata, A. kryophila, A. helvetica satis differt.

  • Basionym
    Achnanthes daonensis
  • Author
    Lange-Bert. 1989
  • Length Range
    10-26 µm
  • Width
    5-8 µm
  • Striae in 10µm

Original Images

Orig Iillustr
Orig Descr 4

Cite This Page

Potapova, M. (2010). Psammothidium daonense. In Diatoms of North America. Retrieved April 14, 2024, from https://diatoms.org/species/psammothidium_daonense


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