I last grew these beans in 2013 in central NY and am hoping to grow them again this year (I know, they're old). Unfortunately I have no memories of where I got the original bean seeds, and I really like the beans. They're extremely productive and appear to be best when shelled, but are also delicious when harvested younger while the pod is still fairly flat. The vines are ~12' long or more when mature. Flowers are pale purple, and both beans and pods have dark purple streaks. My best guess about where I got these beans is from some store-bought bean sold as food.
The bean looks a lot like Swiss Landfrauen to me, but it's doubtful I picked up such a special (heirloom) bean without knowing about it. The bean is reminiscent of Dragon's Tongue also, though it seemed my beans' pods were slightly wider than Dragon's Tongue.
Any help would be appreciated in identifying my striped purple pole bean. Any tips on how to tell apart almost identical cultivars, like Swiss Landfrauen and Dragon's Tongue, would also be appreciated. Thank you!