Bougainvillea arborea is the world's only "true" totally thornless and fragrant Bougainvillea. The bright lavender bracts really catch the eye. But unlike other Bougainvilleas this tree doesn't shed its bracts until they are brown. This tree is in the Fairchild Tropical Botanical Garden and I know of one at the Kampong (also a botanic garden). I am told that it is in the market, but I have not seen one in a private garden.