• Category
  • Length Range
    18.4-23.4 µm
  • Width Range
    5.5-6.1 µm
  • Striae in 10 µm
    11.7-14.3

Identification

Description

Valves are clavate with broadly subrostrate to subcapitate headpoles and capitate footpoles. The axial area is linear and narrow. The central area is a transverse rectangle, formed by 1 to 3 shortened striae on each side of the valve. The 4 longest striae bordering the central area have an isolated stigmoid on the ends closest to the proximal raphe ends. The raphe is filiform, with the proximal ends slightly inflated and deflected to the secondary side of the valve. The striae are radiate, transitioning to parallel at the head pole and strongly radiate at the foot pole.

Autecology

This variety was originally described from Pennsylvania (Patrick 1971). Since then, it has been found in Maine (images on this page) and has been reported in southeast rivers (Bishop et al. 2017).

Gomphonema Olivaceoides Var Hutchinsoniana Diminution  Gc112789
Credit: Gina LaLiberte
Size diminution in one population from Maine (ANSP GC 112789).

Original Description

Valve lanceolate with narrowed rostrate to distinctly capitate apex and capitate base. Axial area linear, narrow, at the central area the margins of the axial area are marked by 4 puncta. Central area transverse with 1 or 2 shortened striae on each margin of the valve. Raphe linear, not extending or only slightly extending into the central area. Striae radiate throughout the valve, indistinctly punctate. Striae, 13-14 in 10 μ. Length, 15-18 μ. Breadth, 5-6 μ.

  • Author
    Patrick 1971
  • Length Range
    15-18 µm
  • Width
    5-6 µm
  • Striae in 10µm
    13-14

Original Images

Gooliva Hutch Orig Desc Plate
Gooliva Hutch Orig Desc Text

Cite This Page

LaLiberte, G. (2017). Gomphonema olivaceoides var. hutchinsoniana. In Diatoms of North America. Retrieved July 18, 2019, from https://diatoms.org/species/gomphonema_olivaceoides_var._hutchinsoniana

Responses

The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Gomphonema olivaceoides var. hutchinsoniana 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.