I've never heard of them either but they look worthy of a try in the garden.
Not to get too far off topic
but, I'm just starting to get some winter crop seeds planted. Actually, a couple of your seeds, Rick some Ching Chang, I think a mustard and some of the baby bok that I didn't get to grow this spring.
I should look into some winter crops that might grow here for the chickens to forge. Nothing is green here in the winter!