Nuria Mora is one of my favourite street artists. I love her use of flowers and patterns. She is a Spanish artist and since 2002 her work has showed up in cities like London, Milan, Barcelona, Madrid, Berlin, Paris, Tokyo and Los Angeles. In 2010 she did some murals in New Town and other areas in Joburg. The first pic is from Joburg.
Check out some more of her work on her website here.