So, I found some Epazote seeds at tradewindsfruit.com and grew a plant, this year. It took a while to get started, but wow! It really seems to make beans feel nutritious (normally, beans don't make me feel extremely nourished, but I tried some black beans and ham with epazote and Mexican sour cream on spinach-flavored green tortillas, today, and yeah, it worked). The flavor is quite good with beans, too, in my opinion.
Epazote is supposed to reduce flatulence that comes from eating beans, too; I don't have experience there one way or the other to tell you how it works in that regard.
I hope seed-saving is easy for epazote. I want to grow it every year.
Location: SW Idaho, USA
USDA hardiness zone: 6
Elevation: 2,260 feet Profile post