Successful Farming, vol. 13 page 96 (1914)
Keystone is a magnificient hardy yellow climber, with a number of very strong points to recommend it. It blooms in wonderful profusion, and I have found it absolutely immune from the attack of insects. It grows freely and has a wonderful constitution. The buds are beautifully formed and the flowers are perfectly double. It is of a deep lemon color and the fragrance is very much like that of Magnolia blossoms. I have had the Keystone make a growth of fifteen feet the first season, branching freely.