Many of the plants in our garden have a name attached to them. I have grown the Madame Hardy rose, and assumed she was a real woman. Others have a name that is less obviously that of a real person like Anemone nererosa 'Robinsoniana'.   But who are these people whose names are attached to plants. Who was Perry, or Mrs. R.O. Backhouse or the Vicomtesse Byng? It is easy to know who is being honored when you…