It's called 'kacang botol' here, which means 'bottle bean' literally - but there may be some other meaning I'm not aware of; it's also known as the 'four angle bean'. Its Latin name is Psophocarpus tetragonolobus, and is also know as the Winged bean, or Goa bean. I
Anyway, I didn't know all that before, and nor did I know that it's a very good nitrogen fixer and you can eat the leaves and everything. What I did know is that it's very tasty - it has a slightly nutty flavour, different to the standard green bean, slightly watery, type of flavour. It also grows pretty easily. We've just got another batch starting to flower and fruit; WW planted them from seeds from previous plants about two months ago, and some just started spontaneously from pods that fell on the ground.
Here are some photos of a previous batch - I think I tried to follow a specific flower all the way through, but it may not have worked...
The first one shows the first buds and flowersEight days later, the flowers are in full bloom - I find them rather attractive, a delicate gradation of colour
Eight days later, you can see the bean starting from inside the withered flower
and on the same day, the same thing but with a larger bean
Two days later, the bean is just about ready to pick - wait too long and it will become hard and unpleasant to eat. Though you can get new seeds out of the larger pods.
Once they start producing, you easily get a surfeit of beans, and from about four plants we were getting beans for about a month I suppose.