s A Field Guide to the British Seaweeds - NMBAQC

Spongomorpha arcta
Highly branched filamentous and tufted in
morphology and bright green in colour. Cells longer
than broad with reticulate chloroplast consisting of a
fine non-dense network of fibrils, which are clearly
visible under the microscope, apical cells often
slightly bulbous and conspicuous. Fine reticulate
chloroplast also makes the numerous pyrenoids
easily distinguishable. Branches may be straight,
downward growing and rhizoidal or hook shaped
which may lead to filaments become entangled and
rope-like. Often found in moist overhangs within
turfs of other green and red algae on the mid shore
region. May be confused superficially with
Cladophora sp.
Pyrenoids highly
visible as green
discs
Branching and filaments may be straight or
in-rolled forming hooks
Plants are often highly branched and filaments
may become entangled forming ropes