This isn’t roots right?

[Franklikestrees]

Pyracantha air layer after a few weeks. Looks like a fungus to me but I don’t know anything. Any ideas?

 

[Franklikestrees]

The long strands are moss not roots.

 

[WIlliam_Butler_Yeets]

that looks like a mass of callous tissue with some moss sticking to it, the callous would eventually produce roots if you wrap it back up, but should double check to make sure the masses of callous have not made contact to try and bridge the gap anywhere

 

[Gabler]

The tree grew callus tissue to bridge the gap. Cut any callus tissue that bridged the gap and re-pack it with moss.

 

[Shibui]

Not fungus. You've unwrapped it way too early.
As mentioned, the white stuff is the tree growing what plant people call 'callus' Callus can become bark, wood or roots depending what conditions are around it. If you put the moss back on and keep it damp, there should be roots in another month or so. Leave it uncovered with air around and it will form new bark to heal the wound.
Plants are amazing!

 

[leatherback]

Cut any callus tissue that bridged the gap and re-pack it with moss

this