Poison Sumac is another plant that contains urushiol ... Ragweed plants have deeply lobed leaves and greenish-yellow flowers ...

The plant may have yellow or green flowers or yellow-green berries, depending on the time of year. Like poison ivy and poison sumac, poison oak releases an oil called urushiol when it sustains damage.

These dainty, sweet-smelling flowers hide a dark secret ... For example, poison ivy, poison oak, and poison sumac all have leaves grouped in threes. Also, bright, contrasting colors might indicate ...