Lei Greetings. Leis are traditional Hawaiian flower necklaces given as a sign of welcoming and to show affection. Hawaiian flower leis are made of beautiful and colorful blossoms found in Hawaii.Orchids are the most popular flowers for Hawaiian leis. Plumeria and Lehua Blossoms are other common lei flowers.eis are traditional Hawaiian flower necklaces given as a sign of welcoming and to show affection. Hawaiian flower leis are made of beautiful and colorful blossoms found in Hawaii.