cooker i understand your question...and i think i can help...marijuana is classified under DRUG..not weed nor herb
but we use it as an herb...if only for trichomes....and it grows like a weed
so we could categorize it as an herb because we consume it...just like dandelions are weeds but we also eat those and then classify at as an herb or if just the leaves are eaten we call them salad greens
so as for MJ i would classify it as an herb...definitely
edit..people also smoke herbs like sage to get that psychdelic and rosemary is said to be smokedfor ailments like athsma and other problems with the throat and lungs..and drink spices like nutmeg to get that psychedelic high also