Don't forget about cauliflower, lettuce, celery, collards, gai lan and bok choi. I'm very much impressed with the horticultural diversity of this single species

Don't forget about cauliflower, lettuce, celery, collards, gai lan and bok choi. I'm very much impressed with the horticultural diversity of this single species of plant. Also of interest are closely related mustard species and their varieties.