Krammer 1997 Category: Asymmetrical biraphid
SYNONYM(S): Encyonema turgidum var. ventricosum Tempère et Peragallo | Cymbella muelleri f. ventricosum (Tempère et Peragallo) Reimer | Encyonema stoermeri Spaulding, Pool et Castro
Contributor: Sarah Spaulding - August 2010
Length Range: 39-78 µm
Width Range: 19-25 µm
Striae in 10 µm: 11-12
Valves are strongly dorsi-ventral. The dorsal margin is broadly arched, while the ventral margin is distinctly gibbous. Valve length is 39-78 μm; breadth is 19-25 μm. The valve apicies are moderately rounded. The axial area is relatively broad in the central valve, narrowing at the valve ends. The raphe branches have a slight arch towards the ventral margin. Each raphe branch is positioned nearly centrally within the axial area. Proximal raphe ends are slightly expanded and dorsally deflected. Distal raphe ends of the raphe curve slightly to the dorsal margin, but are deflected ventrally near the valve apices. The dorsal striae are divergent. Externally, the rows of dorsal areolae closest to the central area are oval, and become lineolate. Dorsally, central striae number 11-12 in 10 μm, and distal striae number 5 in 5 μm. Ventrally, central striae number 9 in 10 μm, and distal striae number 6 in 5 μm. The density of areolae within a central, dorsal stria is 9 in 5 μm.
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.
Spaulding, S.A., Pool, J., Castro, S. and Hinz, F. (2010). Species within the genus Encyonema Kützing, including two new species Encyonema reimeri sp. nov. and E. nicafei sp. nov. and E. stoermeri nom. nov., stat. nov. Proceedings of the Academy of Natural Sciences of Philadelphia 160(1):57-71. 10.1635/053.160.0107
Tempère, J. and Peragallo, H. (1889). Diatomées Collection [Text and Tables of Collection des Diatomées du Monde Entier, ed. 1]. Imprimerie Hy-Tribout, 43 Rue St. Paul, pass. St. Paul, Paris. pp. 1-62 (Table des provenenaces), pp. 1-304.
The name Encyonema stoermeri Spaulding, Pool et Castro was published in 2010, but the authors did not recognize that the type had been previously published as Encyonema temperei Krammer 1997. The website now reflects the correct name, E. temperei, for this taxon.