Walnut Township is one of eighteen townships in Appanoose County, Iowa, United States. As of the 2010 census, its population was 894. Geography Walnut Township covers an area of and contains two incorporated settlements: Mystic and Rathbun. According to the USGS, it contains six cemeteries: Bohm, Elgin, Forbush, Highland, Shaeffer and Zimmer. References External links US-Counties.com City-Data.com Townships in Appanoose County, Iowa Townships in Iowa