Brassica rapa var. perviridis
Tendergreen is also known as spinach mustard because of its thick, smooth, upright leaves.
It is much milder in flavor than regular mustard greens.
It is both heat and cold tolerant, but when it does go to flower you will have an extra treat.
The flowering stems are tasty raw or cooked.
Tendergreen mustard is great in stir fry, soups and salads.