The dudhi is calabash or bottle gourd. It isn't specifically Indian. It grows all over Asia, in Europe and the USA. It is thought to have originated in South Africa. Round here it is most often used in soups and hotpots.
36 minutes ago, Thanks for the Crepes said:
The first link in the above quote is to luffa or loofah, one of my favourite vegetables. Again, not specifically Indian.
I like it steamed with garlic.
Steamed Luffa with Garlic
It is often stir fried with eggs, too.
Your third link seems to be the same as your first. Was their a third vegetable you wanted to ask about?