Valves are lanceolate to lanceolate-elliptic with slightly protracted, broadly rounded to attenuate ends. Striae are parallel in the center becoming radiate toward the apices. The elongate central nodule results in a large gap between the proximal raphe ends. Internally, helictoglossae are present at the raphe ends, at least 3 µm from valve apex. Apical pore fields are present.
Bogan, D. (2013). Brebissonia lanceolata. In Diatoms of North America. Retrieved November 21, 2024, from https://diatoms.org/species/brebissonia_lanceolata1
The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Brebissonia lanceolata 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.
