Scientists just figured out why cannabis smells like a skunk's butt.

For a long time, the exact molecule that gives weed its signature scent was unknown, but hiding in plain sight, or at least, in plain scent. Most research on Mary Jane before this had focused on terpenes and terpenoids, which are hydrocarbons that give most plants their smell.

Terpenes give different strains of weed scents that cannabis connoisseurs might describe as "woody," "citrusy," "floral," or "peppery." At least, underneath all the skunk. But new research has discovered a brand-new family of strongly-scented molecules called volatile sulfur compounds in cannabis plants. We find other families of VSCs in more pleasantly aromatic plants like garlic and hops.

But we also find VSCs in less delicious places, like the defensive spray used by skunks. So it turns out common intuition was right in describing the weed scent as "skunky."