Beyonce and Jay-Z's baby Blue Ivy isn't just the youngest person to appear on the Billboard charts -- she's also the youngest person to have her own strain of marijuana named after her.

TMZ has learned, multiple weed dispensaries in Hollywood are cashing in on hip hop's baby princess ... by selling a new strain of marijuana called "OG Blue Ivy."

Obviously Bee and Hova didn't sign off on the new strain  -- but so far, none of the dispensaries have received any sort of legal notice from the couple.

99 problems, but a kush ain't one.