It seems to be a native of India. Can anybody let me know its full name? In local vernacular, it is called 'kanakambara'.
Crossandra infundibuliformis - or some other Crossandra species.. =) My friend gave me some kanakanmbara seeds she bought from India ;)
There's even a variety with green flowers (don't know the botanical name) which I've had for a couple of years. It died back after a hard freeze in December and I'm not sure it will come back. (Yes, Dummy me left it planted in a flower bed, exposed to the harsh elements...)
Thanks Evert, it is what you have said. http://www.hinduonnet.com/thehindu/seta/2001/11/08/stories/2001110800220400.htm