For hundreds of years, giving flowers has been a social means of communication. In the United States, flowers are often given during rites of passage, for commemorating special occasions or as a heartfelt gift between loved ones and friends. Flower gifting also occurs in most countries around the world. However, the meanings and traditions often vary.
While students traditionally gave their favorite teacher an apple in past years, in China, teachers are given flowers. Peonies are by far the flower most often given in China. They are also quite popularly used for weddings. Strangely, potted plants are not considered a pleasant gift among Asian cultures. The people believe that like a plant confined by a pot, the gift symbolizes a binding or restriction.
In Russia, in lieu of giving birthday presents, the guest of honor receives a single flower or an unwrapped bouquet. Floral arrangements or baskets are not given. Russians celebrate a holiday known as Woman's Day. Traditional gifts include red roses, hyacinths or tulips. When there is a funeral or other occasion where someone wishes to express sympathy, carnations, lilies or roses are given in circular configurations, which signify the transition of birth, life and death to rebirth. In this instance, the color of choice is commonly yellow. For joyous occasions, arrangements and bouquets generally contain an odd number of flowers.
In the times of ancient Rome, brides carried flowers to scare away evil spirits and encourage fertility. The Dutch believed that flowers were food for the soul. When invited to someone's home in Great Britain, it is tradition to bring a gift of flowers. All types are acceptable except white lilies, which are usually seen at funerals. Unlike the United States, red roses are a symbol of love. Flowers are generally gifted in odd numbered increments regardless of the occasion. However, the Brits also have superstitions regarding the number 13, so the number is avoided.
In the southern region of the continent, flowers are traditionally given during Christmas. Egyptians are much more conservative and restrict flower gifting to funerals and weddings. While certain flowers may have significant meanings for some, flowers in Las Vegas and across the United States flowers are an accepted gift for any reason desired.
(Source: http://www.fJowersofthefieldIv.com/)