Navicula winona
Bahls 2012 Category: Symmetrical biraphid
BASIONYM: Navicula winona Bahls 2012
LM scalebar = 10 µm = 80 pixels.
Observations
Contributor: Loren Bahls - March 2012
Length Range: 39-52 µm
Width Range: 7.2-8.2 µm
Striae in 10 µm: 12-13
Description
Valves are narrowly lanceolate with gradually attenuated, very narrow subcapitate apices. The raphe is filiform. Proximal raphe ends are bent to the secondary side. Distal raphe fissures are also bent to the secondary side. The axial area is narrow and merges into a lanceolate to rhombic central area formed by irregularly shortened and more widely spaced striae. Striae are radiate at the valve center, become parallel near the valve ends and then convergent at the apices. Areolae are coarse, number 24–28 in 10 μm and are easily distinguished in LM.
Original Description
Basionym: Navicula winona
Author: Bahls 2012
Length Range: 39-52 µm
Width Range: 7.2-8.2 µm
Striae in 10 µm: 12-13
Original Description
Valves narrowly lanceolate with gradually attenuated and very narrow subcapitate ends, 39–52 μm long, 7.2–8.2 μm wide. Raphe filiform, proximal endings bent to the secondary side, distal raphe fissures hooked to the secondary side. Axial area narrow, merging into a lanceolate to rhombic central area formed by irregularly shortened and more widely spaced striae. Striae radiate, becoming parallel then convergent at the ends, 12–13 in 10 μm. Striae lineolae coarse, 24–28 in 10 μm, easily distinguished in LM. For measurements, n = 23 valves.
Original Images
Cite This Page:
Bahls, L. (2012). Navicula winona. In Diatoms of the United States. Retrieved May 24, 2013, from http://westerndiatoms.colorado.edu/taxa/species/navicula_winona
Species: Navicula winona
Contributor: Loren Bahls
Reviewer: Sarah Spaulding
Image Credit: Loren Bahls
- Valves narrowly lanceolate
- Apices very narrow and subcapitate
- Areolae coarse
- Striae widely spaced near central area
Navicula winona has narrowly lanceolate valves with gradually attenuated, narrow subcapitate apices. Areolae are coarse and number 24-28 in 10 μm.
Compare
Navicula wildii also has attenuated apices, but the apices are obtusely rounded rather than subcapitate. Areola density of N. wildii is finer and areolae number 30-36 in 10 μm. The central area of N. winona tends to be a bit larger and the surrounding striae are more widely spaced than in N. wildii.
Navicula wildii
Citations
Bahls, L.L. (2012). Seven new species in Navicula sensu stricto from the Northern Great Plains and Northern Rocky Mountains. Nova Hedwigia, Beiheft 141: 19–38.
Links & ID's
Index Nominum Algarum (INA)
California Academy of Sciences (CAS)
North American Diatom Ecological Database (NADED)
NADED ID:
Autecology Discussion
Navicula winona has been collected from three lakes in Flathead County, Montana. These lakes are alkaline (pH range = 7.2-7.8) with moderate levels of electrolytes (specific conductance range = 140-332 μS/cm). This taxon is named for Lake Winona in the remote North Fork Flathead River Valley on the western edge of Glacier National Park.
Images
Lake Winona, Glacier National Park, Montana: type locality for Navicula winona.
Credit/Source: Billy Schweiger, National Park Service.