This is Georgia O'Keeffe's Red Canna. She was reknowned for her paintings of flowers which were banned from some galleries because of their suggestive sexual content.
O'Keeffe's Grey Line with Black, Blue, and Yellow.
Nick Bantok is both an artist and the author of several books: The Griffin and Sabine Trilogy, The Venetian's Wife, The Forgetting Room, and others. This particular collage is a postcard from Griffin and Sabine.
Another Bantok collage the name of which I can't recall. It's from The Golden Mean, the third book in the Griffin and Sabine Trilogy.