Bougainvillea. Photo: Dan Culbert. Bougainvillea is a tropical vining shrub that comes in a wide array of bright and fanciful colors. The flowers are actually modified leaves, called bracts, that are long-lasting and bright.The colorful bracts outshine the plant's true (but tiny) flower, much like a poinsettia.ougainvillea. Photo: Dan Culbert. Bougainvillea is a tropical vining shrub that comes in a wide array of bright and fanciful colors. The flowers are actually modified leaves, called bracts, that are long-lasting and bright.