The lyricks are derived from a poem "Braes of Balquidder" written by Scottish poet Robert Tannahill circ 1760 or so. I'm not sure of the tune origons but two versions that I know of differ slightly, one being "Wild Mt. Thyme" and the other "Braes of Balquidder" can be heard on the Tanahill Weavers Capernaum.

O'Hanrahan ...of both Irish and Scottish heratage, but then we all know the Scots are just an Irish tribe.