Cochlospermum religiosum

Cochlospermum religiosum is a flowering plant from the tropical region of Southeast Asia and the Indian Subcontinent. It is a small tree growing to a height of 7.5 m usually found in dry deciduous forests. The name religiosum derives from the fact that the flowers are used as temple offerings. It is also known as Silk-Cotton Tree because the capsules containing the seeds have a fluffy cotton-like substance similar to kapok.  Another common name is Buttercup tree because its yellow and bright flowers look like large-sized buttercups. 
In Thailand it is the provincial tree of Nakhon Nayok Province.