[header] How to identify poison oak [title] Learn about poison oak. [step] Poison oak is similar to its close relatives poison ivy and poison sumac because they are all members of the same botanical family. The most common type of poison oak, known as western poison oak, grows most commonly along the pacific coast in oregon, washington, and california. 
It can grow as a small shrub in open spaces or as a climbing vine in shaded forest areas. [substeps] Other varieties of poison oak include atlantic poison oak, which grows in the southeast us.