Yes, you are correct in the name looking like Potley. I believe this is the nickname that Beat Rebsamen (Turnipseed) went by when he immigrated to South Carolina. There are a lot of Turnipseeds descended from these two brothers, though mine are through Beat "Potley"'s brother, Hans "John" Turnipseed. John is in the 1790 Census for Richland Co., SC as John Turnapseed (with an a). It seems misspelling of the surname was not terribly uncommon.
My ancester, Henry John Turnipseed (grandson of this Hans "John" Turnipseed) is in the 1840 - 1860 Censuses in Augusta Twnp., Carroll Co., OH, 1830 in Paris Twnp., Stark Co., OH. In 1820 there are 2 different Henry Turnipseeds. One in Aldie Twnp., Loudoun Co., VA, and the other in Fayette Twnp., Paint Co., OH. I am leaning towards the OH Henry because in 1830 he is in OH and the ages of the householders are closer in the OH than the VA census. This other Henry then is possibly an Uncle.
The 1840 Census spelled the surname Twinifseed, 1830 spelled Timmfreed and 1820 Tirnipseed.