Late spring in the Portuguese capital sees jacaranda trees burst into bloom, lining the city's streets in vivid colours of lilac-blue, much to the delight of tourists on the lookout for photo opportunities. The exotic tree, introduced in the 19th century from South America, is the "harbinger of summer" says Ana Luisa Soares, director of the Ajuda Botanical Garden in Lisbon. IMAGES AND SOUNDBITES ARRANGED IN SEQUENCES