3 ideas
Wakefield teaches the Linnaean sexual system, which groups flowering plants into classes largely by the number, relative length, and arrangement of their stamens, and subdivides many classes into orders by counting pistils. The final class gathers plants whose reproductive organs are concealed, so the method rests largely, but not entirely, on features a beginner can see and count in a flower.
Felicia delivers her botanical lessons as letters to her sister Constance, who is away visiting their aunt for the summer, so each new term is explained to a listener who needs it spelled out. The form presents instruction as one sister's report to another rather than a formal lecture, and shows observation being turned into explanation.
The book argues that studying plants gives girls a serious, systematic intellectual discipline that can be pursued through walks and gardens within the domestic sphere. Botany is presented as training in close observation, precise naming, and ordered reasoning that also cultivates a sense of wonder and religious gratitude at the design of nature.