Pinney, p 84-85 says the parents of Perla Rosa were Merveille des Rouges X R. roulettii. (Rouletii). Vintage offers Perla Rosa saying it is a compact grower. They have a photo.

Pinney p. 85 describes Climbing Perla Rosa, a climbing sport of Perla Rosa. This climbing sport seems to be the identity of the found small climbing mini, "Willitts Climbing Rouletii", that was offered by Heritage Rose Gardens.