Tu es Petrus, et super hanc petram aedificabo ecclesiam meam.
As an Italian scholar has said, Dante's “rime pietrose” are a “questione pietrosa.” The rime pietrose—Pietra or Petra poems—are, strictly speaking, a small group of poems in which there is word-play on the lady's name and disposition. One thinks of Shakespeare's “Will” sonnets. Barbi allots to the Petra group one sestina, one sestina “doppia,” two canzoni, and a doubtful sonnet. Other critics would add more poems as being similar in mood and motive. D'Ancona, conceiving la Pargoletta, la Petra, la Donna Gentile, and Lisetta as “una persona in diversi atteggiamenti,” would include in one cycle nearly all Dante's lyrics not addressed to Beatrice. Certain others would identify la Petra with one other of Dante's ladies. Thus Zenatti, Santi, Misciatelli identify her with la Pargoletta; Serafino identifies her with Gentucca. At the other extreme, Federzoni rejects the idea of a Petra group altogether.