All flowers have their own language and each of one them can send a different message.  Since ancient times, flowers have been a way to make known and transmit many types of sentiments.  The language of flowers takes its origins from the Orient and been passed from generation to generation and from culture to culture, through Ancient Egypt, the Middle Ages, the Renaissance, etc. to reach the Romantic era, the time when they reached their highest peak.

There is a language associated with flowers and for every occasion.  For example, the red rose is synonymous with love, the yellow with friendship, the white with fear, etc.  Other examples: the white daisy signifies innocence and purity, which is why it is often related with childhood; the gardenia signifies happiness, the orange blossom - chastity, the tulip - desperate love if it is yellow and a subtle declaration of love if it is red; the carnation signifies distinction and nobility, and the lily - innocence, purity and joy.

But we shouldn't only take into account the flower in itself.  The form of presenting this gift is also important, so that if we give a bouquet of flowers, the ribbon will tell us for whom the sentiments of the bouquet are expressed.  That is to say, if the bow is situated at the left, it means that the sentiments expressed refer to the sender, while if it is at the right, it references the recipient.

Furthermore, the message changes function with the position of the flower and whether it is budded or blooming. So, a flower with the stalk pointed up signifies an evil or backstabbing gesture.
Because of this, you cannot give the gift of flowers lightly.  You must consider three things: what each one represents, what you want to communicate, and what is the favorite flower of the person you are giving it to.

At the same time, you shouldn't underestimate the color of the flowers as they can provoke certain attitudes and emotions that affect the depths of the human mind.