plant

I am looking for information on a plant that my grandmother used to have and she called it a "sweet pea bush" it was a shrub and they called it a "sweet pea bush" because the blooms looked like a sweet pea bloom. I don't remember much about the way it looked other than it had what looked to me...

...but do they really taste that much different that one would get all these different varieties? Or do they just get those varieties so they can say they are growing all these varieties? Was visiting a UK garden site and they have more names for tater varieties over there than you can shake...