Hum, looking over the spell, it doesnt seem to say its announced or anything. But it does say the limb can not be used for locomotion, wielding weapons, spellcasting.
It does say that it makes the limb withered. I would say that if the limb is visable the wither would be visable, but thats just my 2 cents, unless someone can find something more solid. Sadly its not on the list of visable spell effects.
