Wildflower

Remember that song from The Beegees album "Living Eyes"? It keeps ringing in my ears everytime I see this blooming shrub that grows in front of the compound wall to my house. I don't water it. It just grows wild and I am hesitant to have it removed. The flowers fully open at around 11.00 A.M during the day and during the night the flowers have completely shrunk themselves into small tube like things. Can anyone tell me what plant this is?