This spring, the first really fresh vegetable I tasted was a bag of local rocket (arugula) picked that day from a greenhouse. The leaves were less than eight cm (three inches) long, lightly peppery, clean, green, and mild, impeccably delicious. Rocket is one of the brassicas (along with cabbage, radishes, turnip, mustard, cress, kohlrabi, kale), and even mild young rocket has the three tastes typical of brassicas: sweetness, pepperiness, and sulfur. The rocket I’ve always grown is the opposite of the kind I bought. Mine is untamed, intense: nutty, peppery, sweet, bitter, spicy, pungent — skunky isn’t too strong to describe the smell, although everything falls into place when you taste, or at least I feel that way. One August, to encourage new growth I cut back a row of the flowering stalks, and afterward my hands smelled rubbery, almost like diesel. (I should have just pulled the plants.) The spring greenhouse leaves showed barely any of the sulfur side of rocket. I add that the powerful kind has one more flavor, something that to me recalls a malty, whole-grain cooked cereal.