Caloneis lewisii

R.M.Patrick 1945      Category: Symmetrical biraphid

REPORTED AS: Caloneis schumanniana (Grunow) Cleve (Krammer & Lange-Bertalot 1986, Fig. 171: 4) 

Caloneis bacillum


Caloneis silicula

LM scalebar = 10 µm = 40 pixels.


Contributor: Matthew Keith | Barry Rosen - June 2012
Length Range: 25-42 µm
Width Range: 11.5-13.5 at center of valve, 6.5-10 near the apices µm
Striae in 10 µm: 19-22


The valve margin is triundulate, with the central undulation being slightly broader than the distal undulation. The apices are broadly rounded to cuneate. The axial area is narrow, becoming apiculate toward the apices. The central area is large and rhomboidal in shape with two lunate markings within the central area, on each side of the central nodule. The raphe is straight and filiform near the distal and proximal ends, becoming slightly lateral between them. Proximal raphe ends are slightly expanded. Striae are parallel, becoming radiate toward the central nodule and slightly divergent at the ends.

Krammer and Lange-Bertalot (1986) illustrate a very broad concept of C. schumanniana (Grunow) Cleve which includes C. lewisii. For the US flora, the shape and size series of C. lewisii is treated as distinct at the species level.

Original Description

Author: R.M.Patrick 1945
Length Range: 27 µm
Width Range: 8.7 µm
Striae in 10 µm: 19-20

Original Description

Valvae bis constrictae longae 27 µ ad medium 8.7 µ apicibus cuneatae ; striis transversis 19-20 in 10 µ ; area axiali angusto, nodulo centrali majusculo subquadrangularis signis lunatis duobus crasso. Type: Illinois, Du Page County, 2423 F. Drouet, P. C. Standley and J. A. Steyermark (A-2018).

Original Images

Cite This Page:
Keith, M., and Rosen, B. (2012). Caloneis lewisii. In Diatoms of the United States. Retrieved April 26, 2018, from

Species: Caloneis lewisii

Contributor: Matthew Keith | Barry Rosen

Reviewer: Rex Lowe


Patrick, R.M. (1945). A taxonomic and ecological study of some diatoms from the Pocono Plateau and adjacent regions. Farlowia 2(2):143-221.

Patrick, R.M. and Reimer, C.W. (1966). The Diatoms of the United States exclusive of Alaska and Hawaii, V. 1. Monographs of the Academy of Natural Sciences of Philadelphia 13.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Caloneis lewisii CAS

NCBI Genbank Taxonomy

Caloneis lewisii NCBI

North American Diatom Ecological Database (NADED)

NADED ID: 12014

Autecology Discussion

Caloneis lewisii thrives in a wide variety of environments ranging from flowing streams to small lakes and ponds in the midwestern U.S., including shallow, temporary waters.