Bengal Trumpet Vine/Blue skyflower

Plants may grow to about 20 metres in height and have a tuberous root system with a deep tap root. The stalked, opposite leaves, which have a rough surface, are quite variable in shape. They may be triangular or ovate and the margins may be toothed, lobed or entire. Length is up to 20 cm and width is up to 6 cm. The blue to mauve flowers are about 8 cm across with a 4 cm long tube that is pale yellow inside. These are followed by pods containing seeds that are ejected several metres upon ripening. Plants also reproduce from segments that are washed down watercourses (Wikipedia).