Encyonema neogracile

Krammer 1997      Category: Asymmetrical biraphid
SYNONYM(S): Encyonema gracile Rabenh. 1853 
REPORTED AS: Cymbella lunata (Patrick and Reimer 1975, p. 46, plate 7, figs. 11-14) | Cymbella gracilis (Krammer and Lange-Bertalot 1986, p. 308, fig. 120: 3-5) 

Encyonema minutum var. pseudogracilis


Encyonema nicafei

LM scalebar = 10 µm = 80 pixels.


Contributor: Loren Bahls - June 2016
Length Range: 19-41 µm
Width Range: 5.5-6.7 µm
Striae in 10 µm: 12-15


Valves are cymbelloid and narrow, with narrowly rounded apices. The dorsal margin is moderately arched. The ventral margin is weakly convex to nearly flat with a slightly tumid central valve. The central area is slightly wider than the axial area,. The raphe is lateral, narrowing near the proximal ends and terminal fissures. Proximal raphe ends are deflected dorsally and terminate in inconspicuous central pores. Distal raphe fissures are long and curved ventrally. Striae on the dorsal side are radiate and more widely separated at the valve center than near the apices. The median dorsal stria has a single isolated areola near the central area. The shorter striae on the ventral side are parallel to radiate near the valve center, becoming convergent near the apices. Areolae in the striae are fine and number 30-35 in 10 µm.

Original Description

Author: Krammer 1997
Length Range: 16-50 µm
Width Range: 5.5-6.6 µm
Striae in 10 µm: 12-14

Original Description

Original Images

Cite This Page:
Bahls, L. (2016). Encyonema neogracile. In Diatoms of the United States. Retrieved April 22, 2018, from http://westerndiatoms.colorado.edu/taxa/species/encyonema_neogracile1

Species: Encyonema neogracile

Contributor: Loren Bahls

Reviewer: Diane Winter


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

Patrick, R.M. and Reimer, C.W. (1975). The Diatoms of the United States, exclusive of Alaska and Hawaii, V. 2. Monographs of the Academy of Natural Sciences of Philadelphia 13.

Rabenhorst, L. (1853). Die Süßwasser-Diatomaceen (Bacillarien) für Freunde der Mikroskopie. Leipzig, 72 pp.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Encyonema neogracile CAS

North American Diatom Ecological Database (NADED)

NADED ID: 110045

Autecology Discussion

Encyonema neogracile is widespread and common in lakes, fens and mossy seeps in the mountains of the Northwest United States. These waters typically have low concentrations of nutrients, low to very low electrical conductance, and circumneutral pH.


Kootenai Pond, Glacier National Park, Montana: home of Encyonema neogracile

Credit/Source: Loren Bahls