Sounds like tea leaves. Tea contains caffeine, which is a drug. And like St. Johns Wort which is also a drug, which doesn't even have to be dried to make a tea, you can brew with fresh flowers.
Debating legalities and social consciousness about use of marijuana when off the clock vs. time it stay in the body, and on the clock vs. cigarettes on the clock is all well and fine. But if it walks like a duck and quacks like a duck, in other words has a brain alteration effect like other close-to-nature drugs, it's a drug.