s A Field Guide to the British Seaweeds - NMBAQC

Blidingia sp.
This is a tubular and foliose species, although due to its small
size it often appears filamentous in form. It is found growing at
the top of the shore often in mat form, covering large boulders.
It is also found growing epiphytically on Fucus species
although microscopic examination is required to distinguish it
from Ulothrix species which are also known to grow on Fucus
sp. The cells are generally small and cellular contents may be
hard to distinguish but this characteristic may be used to
separate it from Enteromorpha sp. where cells are larger. It
has a round basal discoid holdfast unlike Enteromorpha which
has rhizoidal cells. Some specimens also appear to have a
slight margin where the outer filament walls seem thicker.
Blidingia is also common in estuaries and on artificial
structures e.g. bridge supports.
Cells usually less than
10um, so do not appear to
have easily distinguishable
contents
Blidingia growing on small boulders
Cellular arrangement of
Blidingia showing thickened
filament walls and small size
of cells