Common Beans (Phaseolus vulgaris)
Beans are what make seeds cool. The diversity of types is endless and new types are infinite. The common bean cohort can be divided into pole and bush types, although there are ones that we will call semi-bush types falling somewhere in between. These can be further categorized into snap, string, wax, shell, kidney and dry beans. There are more types than you will find on the grocery shelves with Seed Savers Exchange offering over 2,000 alone.
Another great advantage to saving beans are they pretty well inbreed, which means varieties can be saved much closer than outcrossing species. Insect cross-pollination does occur but if distinct types are grown you should be able to tell if they have crossed by looking at the seed coat.
Harvest can often be later than desirable in some areas like ours. If so, harvest green plants prior to a freeze and store in a cool dry place upside down until dry. The pods can be threshed by flailing. The recovered beans if intended to store are to be dried to the point where a hammer blow shatters rather than mashes the seed. Beans do take up moisture so an air-tight container is advised.