Prasiola crispa

Prasiola crispa is a small green marine or terrestrial seaweed.
Taxonomy.
The species, first described as "Ulva crispa" Lightfoot, is the type of the genus "Prasiola" .
A lectotype was nominated for the species, the type location of which was provided in accompanying notation as walls that faced north and were favoured as urinals.
The specific epithet is said to translate as "crisped", a reference to the irregular convolutions of the species.
Description.
This is a small green alga growing to about 6 cm long. The frond is round in shape, flattened. Generally one cell thick, the cells arranged in rows or in groups of four.
Reproduction.
Reproduction is by akinetes and aplanospores.
Distribution.
Recorded from Iceland the British Isles including the Isle of Man, Mediterranean, New Zealand, Japan and the Atlantic shores of North America.
Conservation status.
In Iceland, it is red listed as a vulnerable species (VU).