Encyonema paucistriatum

(A.Cleve) D.G.Mann 1990      Category: Asymmetrical biraphid
BASIONYM: Cymbella paucistriata A.Cleve 1934

REPORTED AS: Cymbella paucistriata (Krammer and Lange-Bertalot 1986, p. 305, plate 119, figs 14-16) 

Encyonema obscurum


Encyonema pergracile

LM scalebar = 10 µm = 80 pixels.


Contributor: Loren Bahls - September 2016
Length Range: 25-39 µm
Width Range: 4.9-6.1 µm
Striae in 10 µm: 8-11


Valves are lunate with rounded apices. The dorsal margin is moderately arched. The ventral margin is flat to slightly tumid. The axial area is narrow. The central area is very small and asymmetric, formed by a slight shortening of the median dorsal stria. Raphe branches are straight, with proximal ends deflected to the dorsal side. Distal raphe fissures are curved ventrally. Striae on the dorsal side are slightly radiate and more widely separated at the valve center than they are near the apices. Specimens are variable in stria density; some valves have irregularly spaced striae. Striae on the ventral side are short, and more or less parallel throughout. Areolae in the striae are fine.

Original Description

Basionym: Cymbella paucistriata
Author: A.Cleve 1934
Length Range: 30-35 µm
Width Range: 6-7 µm
Striae in 10 µm: 7-8

Original Description

Original Images

Cite This Page:
Bahls, L. (2016). Encyonema paucistriatum. In Diatoms of the United States. Retrieved April 25, 2018, from http://westerndiatoms.colorado.edu/taxa/species/encyonema_paucistriatum

Species: Encyonema paucistriatum

Contributor: Loren Bahls

Reviewer: Sylvia Lee


Cleve-Euler, A. (1934). The diatoms of Finnish Lapland. Societas Scientiarum Fennica. Commentationes Biologicae. 4(14):154 pp.

Krammer, K. (1997). Die cymbelloiden Diatomeen. Eine Monographie der weltweit bekannten Taxa. Teil 1. Allgemeines und Encyonema. Bibliotheca Diatomologica 36: 1-382.

Krammer, K. and Lange-Bertalot, H. (1986). Bacillariophyceae. 1. Teil: Naviculaceae. In: Ettl, H., J. Gerloff, H. Heynig and D. Mollenhauer (eds.) Süsswasserflora von Mitteleuropa, Band 2/1. Gustav Fisher Verlag, Jena. 876 pp.

Links & ID's

Index Nominum Algarum (INA)

Transfer INA
Original INA

California Academy of Sciences (CAS)

Encyonema paucistriatum CAS

North American Diatom Ecological Database (NADED)

NADED ID: 110049

Autecology Discussion

The specimens shown on this web page were collected from wetland habitats on the tundra in Nunavut, Canada (photos below). These wetlands have circumneutral pH, low conductivity, and low concentrations of bioavailable nutrients. This species was described from material collected in Finnish Lapland (Cleve-Euler 1934) and has also been reported from oligotrophic waters in northern Sweden and the European Alps (Krammer and Lange-Bertalot 1986).


Wetland pool near Baillie River, Nunavut, Canada: home of Encyonema paucistriatum

Credit/Source: Beverly Boynton, Adventurers and Scientists for Conservation

Closeup of wetland pool near Baillie River, Nunavut, Canada. The reddish color is caused by precipitated iron hydroxide.

Credit/Source: Beverly Boynton, Adventurers and Scientists for Conservation

Wet hummocks near Baillie River, Nunavut, Canada: home of Encyonema paucistriatum

Credit/Source: Beverly Boynton, Adventurers and Scientists for Conservation