The city's International Flower Exhibition will kick off at the Shanghai Botanical Garden in Xuhui District this Thursday. A sea of dahlia, rose, tulip, peony and lily, including some rare species, will be on show. In total, more than 20,000 flowers from over 50 species will be put on display. But it's the Dahlia, native to Mexico, that will take center stage — it's the theme flower of this year’s exhibition.