Matt, I've grown Melampodium a couple times, but I have no idea what the cultivar you're looking for is. I would ask someone at the gerden center, where you bought the ones you liked. They might remember the name. This link has a list of cultivars that you can look at to possibly narrow the search down. It's been a while, so maybe you already solved this riddle. https://hgic.clemson.edu/factsheet/melampodiu

Thanks for that list, Jay. No, I haven't figured it out yet. And the garden center does not know. They do some of their own growing outside the city, and then also order in from largely from Missouri, Tennessee, Louisiana, and Central America. Although they look like a homey little garden center, they actually don't seem all that informed or interested in the plants they sell.