Aquatic milkweed is native to much of the southeastern United States and along the Mississippi River. The green states on the map featured in the images are a part of its native range. Collected in Zone 8b and grows from Zone 5b to 10b
Untested for germination rate but they are clearly loved seeds collected at a home garden with care at the peak of ripeness.
Aquatic milkweed grows in full sun in soil that is continuously wet. It is not rare or threatened but the seeds are difficult to come by since they are seldom collected from their host plants. Seeds and plants are available thru my Amazon affiliate product banners.