Does cotton grow on trees? No, but it sure looks like it on this "cotton tree," known scientifically as Ceiba pentandra and commonly as the Java cotton, Java kapok, silk-cotton, Samauma, or ceiba.
This one was just starting to bloom last week when I first spotted it. From a little distance, the balls of fiber look very much like cotton balls. But they are highly flammable and difficult to spin, so they can't be used as cotton is used. However, they have been used as an alternative for down for stuffing mattresses, pillows, and stuffed animals.