Arugula is an extremely healthy leafy green vegetable that has many amazing powers. In some gangs it's used as currency, for some it's a battle cry. Most often it's supplied by the ever mysterious Gary. Most people try to call him but always reach the wrong number.
Arugula can also be used to deter undesirables and charlatans (much as garlic deters vampiric activities).
Furthermore, it is often said that every time somebody calls Gary, an arugula plant blossoms in the high desert.