This book is a pure plagiarism (100%) and a true shame for Mrs Gore (an overated author).
I still do not understand why this book is considerated as an historical reference on HMF!!!!!
The original work was written by the French Pierre Boitard in 1836 : Manuel complet de l'amateur de roses, Paris, Roret. Mrs Gore never adapt anything to the English taste or knowledge, she never dare to mention Pierre Boitard.
I also have to add here, the fact that at the same time, there was another similar plagiarist of Boitard's book in Germany, Ferdinand von Biedenfeld in 1840 : Das Buch der Rosen, Weimar.