I'll bite. What is it? I like the look of it. Very unusual flower.

MM

The foliage looks like pelagonium but the flower looks like Hymenocallis. My guess is it is perennial but is grown as an annual by gardeners north of zone 9. Only a guess as I have no idea what it is. Al

Trichosanthes anguina

This is commonly known as the snake or serpent gourd and is an annual. If you check around, you might find this is pollinated by night-flying moths.

How interesting! Is that why they have strangely shaped flowers?

Maybe not, see image below.

{{gwi:25962}}

I think it is a curcurbit.

Yes, sure.