hmm. do they come off? are they stuck on or part of the leaf? are
they hard shell scale or just ookiness from hard water? also, are they
stray potting bits that have gotten stuck on? i occaisionally am
given a heart attack by a stray piece of sphag that has lodged
somewhere and i think "eek! scale!" then i poke it and realize it's
sphag.

have you tried wiping yours off? water first, then rubbing alcohol.
see if it makes them run away.

--j_a