Which books of Natural History focus on plants and botany?

In his encyclopaedic work Natural History, the books that focus on botany are Books XII through XIX.12

Within these volumes, Pliny the Elder provided significant insights into Roman gardens, early botanical writings, and the introduction of new horticultural and agricultural species into Italy. Notably, Book XVIII is dedicated to agriculture, offering important information on techniques such as crop rotation and farm management. By recording Latin synonyms for Greek plant names, Pliny also helped make many plants mentioned in earlier Greek texts identifiable to later readers.1