Botany is understood to mean the science that deals with botany. Throughout the ages, scientists from various cultures have studied and described plants. This resulted in taxonomy, the hierarchical classification of plants (and animals), a subscience of (bio)systematics, which also focuses on explaining the diversity of forms of life.
It is useful to know which relationships exist between plants, and to understand connections, also from a culinary point of view. For example, the Piperaceae have in common that they contain piperine, a pungent substance that we also know as pepper oil, and the citrus peppers (Zanthoxylum) contain the pungent substance sanshol.