Thevetia peruviana / Thevetia nerifolia
Thevetia peruviana is an evergreen tropical shrub or small tree. Its leaves are willow-like, linear-lanceolate, and glossy green in colour. They are covered in waxy coating to reduce water loss. Its stem is green turning silver/gray as it ages. The long funnel-shaped sometimes-fragrant yellow (less commonly apricot) flowers are in few-flowered terminal clusters. http://davesgarden.com/guides/pf/go/2248..., http://hi.wikipedia.org/wiki/%E0%A4%95%E...)
Thevetia peruviana is a plant native to central and southern Mexico and Central America. It is a close relative of Nerium oleander, giving it one common name as Yellow Oleander, and is also called lucky nut in the West Indies. I found it in the village Charubeta, Khatima, Uttarakhand, India.
Thevetia peruviana plants are toxic to most vertebrates as they contain cardiac glycosides. Many cases of intentional and accidental poisoning of humans are known. A few bird species are however known to feed on them without any ill effects. These include the Asian Koel, Red-whiskered Bulbul, White-browed Bulbul, Red-vented Bulbul, Brahminy Myna, Common Myna and Common Grey Hornbill.