Hespeus - you are right - The word sally is from the Gaelic " Saileach' = willow.( Ulster). A Sally Wattle is a branch of a thorn hedge with the thorns removed, I was often threatened with a few swipes of a " Sally Rod" when I misbehaved as a child. Which was quite often, my father being a softie meant I never felt the sting of one, just the threat. My ilaws have a house in Co Tyrone called "Sally Garden"