The Basilica - Located behind the Spiral door.
The Atheneum - Go around to the back of the library and the rose is on the side of the building.
The Necropolis - Go down the ramp to the left of the Drake Hatchery Entrance and go around to the right. The rose is behind the rocks.
Dragonspyre Academy - When you enter Dragonspyre Academy go straight, all the way to where the dragon is. Then go behind the building on the left.
The Tower Archives - When you enter this area, stay to the left and keep going left, until you go down some stairs and can't go further. The rose is behind the building on the left.
The Labyrinth - This rose is in the last part of the Labyrinth. Go to the right of the tower and the rose is on a rock.
The Crystal Grove - Go to the second Crystal area and the rose is in the top left quarter.
The Grand Chasm - Use the time crystal to go back in time. When you enter the past, turn right and go to the end of the hallway. The rose is on the right side of the last vault on the left.
Dragon's Roost - When you enter this area, go behind the stone walls on the left and turn left. The rose is behind the first building.
The Crown of Fire - When you enter the room where Malistair is, go around the four undead protectors. There is a ramp on the left and the stone rose is in this area attached to a rock.
So those are the locations of the roses. I hope this guide helps you if you havent been able to find them. Thanks for reading and have fun questing!