Geoffrey was married to Empress Maud, of Germany, daughter of Henry I, King of England and Princess Matilda of Scotland. I do not know if Maud was the mother of Geoffrey's son Hameline Plantagenet de Warren, or if Hameline's mother was a different woman (Browning, Charles H. Americans of royal descent, 7th ed. Baltimore : Genealogical Pub. Co., 1986, pg. 282). If Maud is Hameline's mother, then she would be a direct ancestor. She was also the granddaughter of Malcolm III (Canmore) and Princess Margaret of England, direct ancestor's and parents of David I, direct ancestor.
Interred: St. Julian's Church, Le Mans, Anjou. Burke says the marriage was 3 Apr 1127. The name Plantagenet, according to Rapin, came from when Fulk the Great being stung from remorse for some wicked action, in order to atone for it, went a pilgrimage to Jerusalem, and was scourged before the Holy Sepulchre with broom twigs. Earlier authorities say it was because Geoffrey bore a branch of yellow broom (Planta-genistae) in his helm. Duke of Normandy 1144-1150. (WWW site : Directory of roral genealogical data).