Stodder 1859 Category: Symmetrical biraphid
BASIONYM: Stauroneis baconiana Stodder 1859
SYNONYM(S): Stauroneis nobilis var. baconiana (Stodder) Reimer
Contributor: Loren Bahls - December 2011
Length Range: 73-139 µm
Width Range: 9-18 µm
Striae in 10 µm: 16 in the center, 20 at the ends
Valves are linear-lanceolate, narrowing very gradually to long, protracted, rostrate apices. The raphe is lateral, becoming filiform and straight at the proximal ends. The proximal raphe ends are not expanded. The axial area is narrow and linear, expanding slightly near the central area. The stauros is narrow and rectangular. Occasionally short striae are present in the stauros. Striae along the border of the stauros are parallel, becoming radiate to more steeply radiate near the valve apices. Areolae are round to transversely oblong. Areolae are irregularly spaced near the central area and become more closely spaced toward the apices, 14-18 in 10 µm.
Although Reimer (1961) treated this taxon as a variety (S. nobilis var. baconiana), it is recognized here at the species level, as originally described (Stodder, 1859).
Basionym: Stauroneis baconiana
Author: Stodder 1859
Length Range: µm
Striae in 10 µm:
Bahls, L. (2010). Stauroneis in the Northern Rockies: 50 species of Stauroneis sensu stricto from western Montana, northern Idaho, northeastern Washington and southwestern Alberta, including 16 species described as new. Northwest Diatoms, Volume 4. The Montana Diatom Collection, Helena, 172 pp.
Camburn, K.E. and Charles, D.F. (2000). Diatoms of Low-Alkalinity Lakes in the Northeastern United States. Academy of Natural Sciences of Philadelphia, Special Publication 18, 152 pp.
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.
Reimer, C.W. (1961). New and variable taxa of the diatom genera Anomoneis Pfitz. and Stauroneis Her. (Bacillariophyta) from the United States. Proc. Acad. Nat. Sci. Philadelphia 113: 187-214.
Siver, P.A., Hamilton, P.B., Stachura-Suchoples, K. and Kociolek, J.P. (2005). Diatoms of North America. The Freshwater Flora of Cape Cod. Iconographia Diatomologica 14: 1-463.
Stodder, C. (1861). Diatoms from West Roxbury (descriptions of Stauroneis baconiana and S. pellucida). Proc. Boston Soc. Natural History 7:26-28.
In the Northern Rockies, Stauroneis baconiana has been found in Fish Lake and Three Bears Lake in Glacier National Park and in a few ponds and small lakes in western Montana. These are all small, shallow bodies of water with abundant submerged and emergent vegetation. In these waters pH ranges from 6.1 to 8.6 and specific conductance ranges from 22 to 192 µS/cm. This taxon has also been reported from a stream and ponds in Massachusetts (Reimer 1961, Siver et al. 2005) and from Grass Pond in the Adirondak Mountains of New York State (Camburn & Charles 2000).
Bloody Dick Pond #7, Beaverhead County, Montana: home of Stauroneis baconiana.
Credit/Source: Loren Bahls