Yellow roses are for friendship. Black roses mean farewell. Yellow roses mean friendship. Pink roses mean friendship or sweetheart. White roses mean purity of the mind.
Black roses are for death.
The custom of exchanging flowers may have less to do with romance and chivalry than with anxiety. For the shy or uncertain, handing over a bouquet is often the easiest way to express sentiment. Ancient myths, biblical stories, and fables all assigned meaning to flowers. Floral lexicons were published throughout the 18th century, allowing secrets to be exchanged with a lily or lilac, and an entire conversation to take place in a bouquet. It seems the more popular the flower, the more superstitions and meanings have been associated with it.