A bouquet unit is composed of three components: a ROSE, a STEM, and a POSY. A ROSE is a flower with a long history of being used as a symbol of love and beauty. A STEM is the part of the plant that supports the flower and connects it to the roots. A POSY is a small bunch of flowers, usually tied together with a ribbon or string. Together, these three components make up a bouquet unit, which is often used as a gift or decoration.