What is this poisonous plant?

Question

My boyfriend brushed up against this plant when we were fishing on the Snake River. It was growing on the bank amongst the other plants and tall shrubs. It was rather tall, with long stalks that were a yard or more long. Slender green leaves were long with pointed ends. Some of the larger leaves were golden yellow. My boyfriend merely brushed against the plant and he said that it began stinging right away. In less than a minute little welts about a quarter of an inch in diameter arose where he had come into contact with it. Any help with what it is?

Answer 1

Sounds a little like Poison Sumac but the reaction was a little fast.

Answer 2

It could of been a wild oleander. They sting and itch almost immediately.