vestigial?

i have been dead heading the jerusalem artichoke blooms in the community garden that have shed their petals because they can look a bit scraggly when they die back and we want to keep up appearances...my back yard is not the university ( phew! ) so i have kept the dead heads around to have a look at what jerusalem artichoke seeds look like...the flowers in my stands are in various stages of the cycle ( top two photos ) and some are more mature than others...i pulled the heads off a couple that seemed ready to shatter ( third photo ) and took them inside to separate the seed from the chaff...sunchokes are members of the sunflower family but their seeds are nowhere near as big ( bottom photo )...when i plant jerusalem artichokes this coming autumn i will be planting tubers not seeds...i wonder if the seeds are vestigial of if you can propagate plants from them...are they true seed or vestiges of a predomesticate? you can grow wild potatoes from seeds but i have never ( yet ) encountered seeds form a potato bloom ( there are still potatoes blooming in a few gardens...perhaps it is time for a closer look )...i see yet another winter project coming into focus as i try to germinate and grow jerusalem artichokes from seed...i'm sitting out a semester ( i have been called classless before and will, no doubt , be called that again ) so i have some time to do some research along with pursuing my reading list ( i said i wasn't in school, not that i wasn't learning )...i have ordered broader spectrum bulbs for my basement light fixtures...i have new pots and the floor has been swept..i hear tell this coming winter is to be pretty much a replay of last year's cold and snow...i need something to keep me busy.