PHAEOPHYTA (brown algae)
Petalonia zosterifolia
(Reinke) Kuntze, 1898


Lenght: 3-9 cm
Width: 0.2-2 mm

?
 
Thallus narrow-ribbon-like, flattened, simple, dark brown. Central part composed of a few layers of colourless cells, cortex single-layered. Plurilocular sporangia uniseriate, crowded, covering large areas of the blade. Loose speciments were once found on the shore. Boreal species.