Back in the summer, our beans looked like this:
Right foreground, your basic green bean. We forget the variety, they were planted from last year's crop. Kind of a Blue Lake thingy. Center, farther away, are the runner beans, which shot up ten foot poles and doubled back, coming after us like triffids. But we stood our ground and ate a lot of them. Last year there were two kinds: Scarlet, and Hungarian. We knew what they had done, behind our backs, but we were kind of curious to see how it would turn out. So we planted the two kinds again this year, knowing they had become more or less one kind that would yield multiple characteristics.
Here's what we have saved for seed. Sure enough, the runners had melded. In the three jars at left, the dark blue came out like Scarlets, and the cream with brown spots look like Hungarians. But the violet ones are trying to look like both. Over on the right you have the Blue Lake thingies. They don't cross with the runners.
We'll plant these next year and see what comes of all this. These new runners are not as pretty as either the Scarlets or the Hungarians, but they taste about the same. Over time maybe we'll come up with our own variety. Mendelian mix & match.