From Patricia Griffith at the Clement-Clements-Clemmons DNA Project:
"John Clements b 1631 England, d by 1710, Surry Co VA was imported by Jeremiah Clements into VA in 1635. He married unknown 1st, and Mary (Thompson?) 2nd. John gave deposition in Surry Co VA in 1701 that he was 70 years old. He was a headright for Jeremiah Clements in 1635, and was probably a member of Jeremiah's extended family. He was not a son of Jeremiah as Jeremiah left all his lands to his daughter, Elizabeth Perry. JEREMIAH CLEMENTS HAD NO MALE HEIRS."
https://www.familytreedna.com/public/ClementsClemmonsDNA/
More info here--note, newer editions of "Adventures of Purse and Person" show Jeremiah with no male heirs.
http://www.genealogy.com/forum/surnames/topics/clements/3593/
http://www.genealogy.com/forum/surnames/topics/clements/3599/