Is Ascophyllum nodosum Lichenized ?

In a recent synopsis on Ascophyllum nodosum (L.) LE JOLIS, BAARDSETH (1970) accumulates all Information available on this common brown alga. This author rnentions briefly the presence o£ fungal hyphae that are never absent from any part o£ Ascophyllum and expresses bis uncertainty about the question if these hyphae belong t o the Asconnycete, described from Ascophyllum^ namely Mycosphaerella ascophylli COTTON (1908). The regular occurrence of an endosymbiotic fungus in all Ascophyllum plants appears to be widely unknown or unnoticed among algologists, The association is not