There are bugs, snakes and plants with personal vendetas against you. Face it, It's a jungle out there. It grows just about everywhere and so far, it looks like this summer is going to produce an especially excellent crop. P.I. is extremely variable in its forms, growing as a vine, a ground cover, or upright.
Old vines get very hairy looking.
The leaves are somewhat variable in shape. Poison Oak has more irregular leaves. It produces whitish flowers from August to November that dry and remain for a long time. An oil that the plant produces is responsible for varying degrees of irritation from skin inflammation to blistering. You don't even have to touch it.