I would be surprised if you find Kalpasi (Black Stone flower).

Here is an earlier discussion on Marathi Mughru/Moggu; http://www.mamtaskitchen.com/board/showthread.php?thread_id=218. This to nearest I got to; http://www.nandyala.org/mahanandi/archives/2007/10/14/naaga-keshar-cloves-and-marathi-moggu/

Kalpasi is a lichen, rather than a flower. Its flavour is very earth-like, like a good humid green-house in summer. The main flavour chemical is called geosmin, of the camphor family.

Marathi Mughru is cassia buds, which I have not tasted, but I assume to taste like cassia.

Cassia buds taste like cinnamon but milder and more flowery.