Bahls 2013 Category: Symmetrical biraphid
BASIONYM: Neidium kozlowi var. densestriata Foged 1981
REPORTED AS: Neidium kozlowi var. densestriata (Antoniades et al. 2008, p.201, plate 124, figs. 6-7, 9)
Contributor: Loren Bahls - April 2013
Length Range: 33-55 µm
Width Range: 9.3-11.1 µm
Striae in 10 µm: 17-18
Valves are lanceolate to linear-lanceolate, with subrostrate to subcapitate apices. A longitudinal line is evident along each margin. The axial area is narrow and widens near to the central area. The central area is wide, rectangular and asymmetric, oriented diagonally to the apical axis. Short striae are present at the margins of the central area. The raphe is lateral, becoming filiform near the proximal ends. The proximal raphe ends are hooked and recurved in opposite directions. Striae are oriented diagonally to the apical axis throughout. Areolae number 26-28 in 10 µm.
Basionym: Neidium kozlowi var. densestriata
Author: Foged 1981
Length Range: 37 µm
Width Range: 9 µm
Striae in 10 µm: 18-20
Valvis multo minoribus et striis densioribus a varietate nominata differt. Differs from the nominate variety by having much smaller valves and denser striae.
Antoniades, D., Hamilton, P.B., Douglas, M.S.V. and Smol, J.P. (2008). Diatoms of North America: The freshwater floras of Prince Petrcik, Ellef Ringnes and northern Ellesmere Islands from the Canadian Arctic Archipelago. Iconographia Diatomologica 17.
Bahls, L. (2013). New diatoms (Bacillariophyta) from western North America. Phytotaxa 82(1): 7-28.
Foged, N. (1981). Diatoms in Alaska. Bibliotheca Phycologica, Band 53, J. Cramer, Vaduz, 317 pp.
Neidium fogedii is known only from the type locality and from Upper Pond #56 at the Mexican Cut Nature Preserve in Gunnison County, Colorado. On the date the Colorado sample was collected, water temperature was 12.3 C, pH measured 7.20 and specific conductance measured 102 µS/cm. Both Foged (1981) and Antoniades et al. (2008) report this taxon (as N. kozlowi var. densestriata) from Desperation Lake in the Brooks Range, Alaska, where pH varied between 8.1 and 8.5 and conductivity ranged from 151 to 707 (Antoniades et al. 2008).
One of many high elevation ponds at the Mexican Cut Nature Preserve in Gunnison County, Colorado: home of Neidium fogedii.
Credit/Source: Nature Conservancy