Also known as common turricula, this plant has altered our trek from Mexico to Canada. It thrives in areas affected by wildfires - where tree cover has been removed (burned). We're hiking in SoCal. Thus, drought and lots of burned areas. Ergo, tons of PDB. 

Easy to identify and reeking like pot (or certain thru-hikers), you know when it's near. It's like the poison oak of the San Gabriel mountains, except more dangerous. PDB has grown so thick along the PCT that there are detours to avoid sections overrun by the plant.

It's kind of pretty, but I'll be happy to never see it again.