Reimer 1961 Category: Symmetrical biraphid
BASIONYM: Stauroneis livingstonii Reimer 1961
REPORTED AS: Stauroneis smithii var. incisa (Siver et al. 2005)
Contributor: Loren Bahls - December 2011
Length Range: 28-38 µm
Width Range: 6.6-8.6 µm
Striae in 10 µm: 22-28
Valves are linear-elliptic with subtly triundulate sides and short, narrow rostrate apices. A pseudoseptum is present at each apex. The axial area is very narrow and linear. A narrow, rectangular stauros is variable across specimens; it is slightly expanded or constricted near the valve margins. Short striae may be present within the stauros at the margins. The raphe is filiform. Proximal raphe ends are straight and weakly expanded. Striae are radiate. Areolae are variably spaced and number 22-28 in 10 µm.
Basionym: Stauroneis livingstonii
Author: Reimer 1961
Length Range: 27-33 µm
Width Range: 7.5-8 µm
Striae in 10 µm: 25-26 (middle) to 28 (ends)
Valves linear-elliptic with slightly triundulate sides and narrow rostrate ends. Pseudo-septae present extending into valve about the length of the ends. Axial area narrow, linear. Fascia narrow, linear. Margins of fascia usually with very short striae. Raphe filiform; proximal ends close; distal ends indistinct but appearing to curve slightly over ends. Striae radiate throughout, the relatively strong arch of the valve frequently giving the appearance of curved striae. Striae punctate; puncta towards margins in longitudinally undulating rows. Length 27-33 µm; width 7.5-8 µm; 25-26/10 µm to 28/10 µm near ends; puncta ca. 24/10 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.
Stauroneis livingstonii is widespread in the Northern Rockies in small lakes and fens. The pH of these waters ranges from 6.0 to 8.1 and specific conductance ranges from 10 to 67 µS/cm. Reimer (1961) described this species from material collected in Three Runs Creek, a small dystrophic tributary of the Savannah River in South Carolina. Patrick & Reimer (1966) report it only from the type locality. Since then Camburn and Charles (2000) have reported it from lakes in the Adirondack Mountains and Siver et al. (2005) reported it (as Stauroneis smithii var. incisa) from seven neutral to slightly acidic ponds on Cape Cod.
Upper Two Medicine Lake, Glacier National Park, Montana: home of Stauroneis livingstonii.
Credit/Source: Loren Bahls