• Category
  • Length Range
    39-52 µm
  • Width Range
    7.2-8.2 µm
  • Striae in 10 µm
    12-13

Identification

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.

Autecology

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.

P9230531 1
Credit: Billy Schweiger, National Park Service.
Lake Winona, Glacier National Park, Montana: type locality for Navicula winona.

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.

  • Author
    L.L.Bahls 2012
  • Length Range
    39-52 µm
  • Width
    7.2-8.2 µm
  • Striae in 10µm
    12-13

Original Images

Nwinona Origimag
Nwinona Origdesc

Cite This Page

Bahls, L. (2012). Navicula winona. In Diatoms of North America. Retrieved August 19, 2018, from https://diatoms.org/species/navicula_winona

Responses

The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Navicula winona from all the stream reaches where it was present. Note that the relative abundance scale is the same on each plot. Explanation of each environmental variable and units are as follows:

ELEVATION = stream reach elevation (meters)
STRAHLER = distribution plot of the Strahler Stream Order
SLOPE = stream reach gradient (degrees)
W1_HALL = an index that is a measure of streamside (riparian) human activity that ranges from 0 - 10, with a value of 0 indicating of minimal disturbance to a value of 10 indicating severe disturbance.
PHSTVL = pH measured in a sealed syringe sample (pH units)
log_COND = log concentration of specific conductivity (µS/cm)
log_PTL = log concentration of total phosphorus (µg/L)
log_NO3 = log concentration of nitrate (µeq/L)
log_DOC = log concentration of dissolved organic carbon (mg/L)
log_SIO2 = log concentration of silicon (mg/L)
log_NA = log concentration of sodium (µeq/L)
log_HCO3 = log concentration of the bicarbonate ion (µeq/L)
EMBED = percent of the stream substrate that is embedded by sand and fine sediment
log_TURBIDITY = log of turbidity, a measure of cloudiness of water, in nephelometric turbidity units (NTU).
DISTOT = an index of total human disturbance in the watershed that ranges from 1 - 100, with a value of 0 indicating of minimal disturbance to a value of 100 indicating severe disturbance.