Bougainvillea are woody perennials native to South America, now widely cultivated in warmer areas of the United States. Plants produce vibrant blooms nearly year-round. Bougainvillea flowers are small, inconspicuous, tubular in form and white or yellow in color. Flowers open at sunset and last approximately five days on the plant. They are surrounded by bracts, which are technically modified leaves, designed to attract pollinators.