For the most part, people are intuitive. They know when someone is crushing on them and if they were to receive flowers from that person, it would solidify their thoughts and could be that step that brings on a more meaningful relationship. If someone feels they have been wronged, if they were to receive flowers from the person they felt wronged by, they will quickly relate it as an olive branch reaching out to make amends. No note would even need to be attached with the flowers, other than the name of the sender and the message would be conveyed. It can be the simple gesture of sending flowers that opens the door to forgiveness or love.
As many meanings as flowers behold, those meanings mean nothing if they are not sent to someone to make those meanings and feelings come to light. With out gifting flowers, they are just that, flowers. Regardless of flowers grand beauty, their meanings only become known when you send them.