(Bahls) Bahls 2015 Category: Asymmetrical biraphid
BASIONYM: Encyonopsis weilandii Bahls 2013
Contributor: Loren Bahls - December 2015
Length Range: 33-72 µm
Width Range: 7.5-9.7 µm
Striae in 10 µm: 12-14 at the valve center, 15-18 near the apices
Valves are rhombic-lanceolate and slightly dorsiventral. Apices are rounded and weakly subrostrate, or apices are not protracted. The axial area is narrow. The central area is small and defined by a shortened median stria on the ventral side. The raphe is centrally located and lateral, becoming filiform at the proximal and distal ends. Proximal raphe ends are weakly expanded and deflected dorsally. Distal raphe fissures are comma-shaped, concave to the ventral margin. Striae are radiate near the valve center, becoming parallel then convergent near the apices, The median striae on the dorsal and ventral sides are more distant from their mates than the remaining striae. A single stigma lies at the proximal end of the median dorsal stria.
This is the generitype for Kurtkrammeria. It possesses all of the features that may be found in Kurtkrammeria, but not in Encyonopsis, including a stigma, apically elongate areolae, convergent striae at the apices, and internal anastomosing virgae and external apical pore fields at both poles. At first glance, K. weilandii might be mistaken for a species of Gomphonema, e.g., Gomphonema gracile Ehrenberg. However, Gomphonema species are not symmetric to the transapical axis and the raphe branches are unequal in length.
Basionym: Encyonopsis weilandii
Author: Bahls 2013
Length Range: 33.0-72.0 µm
Width Range: 7.5-9.7 µm
Striae in 10 µm: 12-14 at valve center, 15-18 near the apices
Valves lanceolate, not or slightly dorsiventral. Apices rounded, weakly subrostrate or not protracted. Valve length 33.0–72.0 μm; valve width 7.5–9.7 μm. Axial area narrow. Central area small, defined by a shortened median stria on the ventral side. Raphe lateral, proximal and distal ends filiform. Proximal raphe ends weakly expanded and deflected dorsally. Distal raphe fissures comma-shaped, concave to the ventral margin. Striae radiate, becoming parallel then convergent near the apices, 12–14 in 10 μm at valve center, 15–18 in 10 μm near the apices. The median striae on the dorsal and ventral sides are more distant from their mates than the remaining striae. A single stigma lies at the proximal end of the median dorsal stria.
Bahls, L. (2013). Encyonopsis from western North America: 31 species from Alberta, Idaho, Montana, Oregon, South Dakota, and Washington, including 17 species described as new. Northwest Diatoms, Volume 5. The Montana Diatom Collection, Helena, 46 pp.
Bahls, L.L. (2015). Kurtkrammeria, a new genus of freshwater diatoms (Bacillariophyta, Cymbellaceae) separated from Encyonopsis. Nova Hedwigia . 10.1127/nova_hedwigia/2015/0263
Like other species of Kurtkrammeria, K. weilandii prefers cold oligotrophic waters with circumneutral pH and low conductivity. There are 28 records of K. weilandii in the Montana Diatom Collection, nearly all of them from ponds and small lakes in the Cascade and Northern Rocky Mountains. Most records consist of one to a few specimens on a strewn mount, but K. weilandii was the dominant diatom species in a small meltwater pond on Anderson Pass in Olympic National Park, Washington (photo below). This pond is at 1361 m a.s.l. elevation, measures about 15 m in diameter, and is less than 1 m deep. The water in this pond is essentially snowmelt and rainwater. To date, K. weilandii has been reported only from North America.
Goat Rocks Pond, Cascade Mountains, Washington: Type locality for Kurtkrammeria weilandii.
Credit/Source: Craig Weiland, Adventurers and Scientists for Conservation
Small meltwater pond at Anderson Pass in Olympic National Park, Washington. Kurtkrammeria weilandii was the dominant diatom species at this site.
Credit/Source: Ryan Davis, Adventurers and Scientists for Conservation