Horticultural plant breeding underwent significant development in France in the
nineteenth century. A wide community of breeders, naturalists, botanists and
scholars was interested in plant breeding; some cared primarily about finding the
most effective ways to get new varieties, while others wanted to understand this
new diversity. They faced a number of practical and theoretical problems con-
cerned with the causes of variation, the genealogy of variation, and the nature of
hybrids. This chapter focuses on two of the most widely bred woody plants in
France, roses and pear-trees, in order to highlight the particularities of these per-
ennial plants, both of which propagated vegetatively and showed a high degree of
variation. It aims to explore the ways in which horticulture overlapped with core
debates within the botanical sciences, particularly with concepts of heredity and
debates on the evolution and stability of species.