*All quotes are taken from the Norton Shakespeare, based on the Oxford Edition (1997). The scenes in the Norton are off by one when compared with the eNotes text.
Act II, Scene 2 (Scene 1 in the Norton)
The flower imagery found in this scene relates to Romeo and Juliet's budding romance--it has yet to blossom: "This bud of love by summer's ripening breath/May prove a beauteous flower when next we meet." (163-164)
Act II, Scene 3 (Scene 2 in the Norton)
Friar Lawrence's Cell
The scene opens with Friar Lawrence gathering weeds, herbs, and flowers. As he does this, he explains in detail each one; this shows his deep and thorough knowledge of the plants and their properties: "Within the infant rind of this weak flower/Poison hath residence, and medicine power,/For this, being smelt, with that part cheers each part;/Being tasted, slays all senses within the heart." (Lines 23-26)
The beginning of this scene could be an instance of foreshadowing, in that, Friar Lawrence's knowledge of plants will play a part in attempting to help Romeo and Juliet be together.