• Category
  • Length Range
    20-35 µm
  • Width Range
    7.2-9.3 µm
  • Striae in 10 µm



Valves are elliptical-lanceolate with rostrate to subcapitate apices. Pseudosepta are present at the ends. The axial area is narrow and linear. A distinctive stauros is present, forming the shape of an "X". The raphe is straight and the proximal external ends are turned to the primary side. Striae are radiate. Areolae are small, circular and number approximately 40 in 10 μm.


Capartogramma crucicula is considered the only species in the genus to occur in North America (Patrick and Reimer 1966). It was described from New England (Merrimac River, growing epiphytically on Chara). According to Patrick and Reimer (1966), it is found in New England, Mid Atlantic states, southeastern states, south central states, and the Gulf Coast. They report that larger populations form in brackish waters. Records from southeast rivers are verified in Bishop et al. (2017).

In northern European rivers, it is considered as rare and invasive (Coste and Ector 2000). It is not uncommon in Mediterranean rivers, but its status as invasive is uncertain.

Other species are found in South America (Meltzeltin and Lange-Bertalot 2007).

Original Description

Schizostauron Crucicula GRUN. Striæ oblique, fine, 25 in 0,01 mm. Stauros bifid with very divergent branches, reaching the margins. Length 0,03mm. Breadth 0,009 mm. Pl. III, fig. 44, 1000/1. Merrimac River U.St. on Chara, very rare in a gathering sent by Mr. O. NORDSTEDT. 1)

  • Basionym
    Schizostauron crucicula
  • Author
    Grunow ex Cleve 1881

Original Images

Schizostauron crucicula orig illus
Schizostauron crucicula orig descr


May 28, 2023 - Addition of autecological information

From 10/2011 until 5/2023, this taxon page did not include text in the Autecology section. - S. Spaulding

Cite This Page

Potapova, M. (2011). Capartogramma crucicula. In Diatoms of North America. Retrieved July 24, 2024, from https://diatoms.org/species/capartogramma_crucicula


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