There are aerial roots extending from the main stem. Like its cousins, it's best viewed from afar and the view is lovely when it dons its spring colors . Western Poison Oak probably causes more trouble than any of the other species. As California's most prevalent woody shrub, human infection seems inevitable. Rashes from run-ins with this and the other Toxicodendrons cause more workman's compensation claims for lumberjacks, park rangers and firefighters than any other source.
Firefighters are especially at risk.
Smoke from burning poison ivy is extremely toxic. It can cause lung infections and a rash all over one's body. Air and wind by themselves can't spread the poison. It's a contact dermatitis reaction. Only direct contact with the plant, fomite, or smoke can infect a person.