Flowers and branch tips

Meaning

II.3.5 associates flowers and branch-tips with a purer or more elevated manifestation of a plant's powers. The image extends the argument that virtue is distributed unequally among parts without making the parts belong to wholly different essences. Position and degree of refinement help explain a difference in effect. The stated cause is the purest substance’s tendency to rise highest, while less pure matter remains in lower parts nearer the excrements. Flowers and tips are consequently compared specifically with the trunk and lower parts, not merely with an unspecified less refined plant.

This is not a universal botanical rule that every flower or tip is medicinally preferable or safe. Its local function is comparative: the author needs an ordinary example of more and less within one living subject. The example supports the separation of powers from essential identity and prepares the claim that art may seek a purer portion without inventing a new nature from nothing.