Peltophorum africanum

Peltophorum africanum, the weeping wattle, is a semi-deciduous to deciduous flowering tree growing to about 15 meters tall. It is native to Africa south of the equator. Their yellow flowers bloom on the ends of branches in upright, showy sprays. During spring time it may happen that water drips from the tree's branches, a phenomenon that is caused by the spittlebug Ptyelus grossus. The immature stages of these spittlebugs congregate on the young shoots and derive their nourishment by sucking the tree's sap. While doing so they secrete pure water, which is the cause of the "weeping" effect....read more on Wikipedia.