I have been planting and harvesting sun root for a few years but I've never been able to harvest the actual seeds of the plants, regardless of having the flowers atracting insects.

Has anyone been able to harvest the seeds? If so, how and when? My intention is to try to grow from seed and see if some variation occurs.

My sun roots develop the usual yellow brownish tubers but occasionally I find some which are reddish or even deep purple; the pulp remains white or lightly yellow but the flavour profile changes drastically, with the purple ones having a very pronounced hazel nut hint.