This post is part of the "Trees of the Tropics" series and has been crossposted from Trees, plants and more.
I came across this tree recently and was told that it is the memecylon umbellatum tree, common in the TDEF (tropical dry evergreen forest) regions of south India and Sri Lanka.
From a distance the entire tree appeared to be covered in a mauve/purple/blue haze. The ground below was also seemingly covered with chalk powder of the same colour - closer inspection showed this to be due to the fallen petals. Such a treat for the eyes!