If it will wash off (I don't mean scrub off) they aren't roots.
But if they are roots, will they damage easily?

You should have seen small white filaments growing out at right-angles
to start with. These may branch out and form lots more filaments to
resemble cotton wool, I don't know, I've never tried that with rosemary.
I just poke the cuttings into the ground and keep them shaded and well
watered.
Hmm, sounds like they might be the beginnings of roots then. Guess I
wait and see.

Thank you for the advice.

Kerry