There are Mimosa species that have a special characteristic; when they're touched, they fold their leaves, then re-open it a few minutes after. <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />  
The Sensitive plant.  Northern Whitecedar (
Thuja occidentalis) 
An evergreen coniferous tree in the cypress family (even not a cedar <img src="/ubbthreads/images/graemlins/tongue.gif" alt="" />), native to the northeastern US and southeastern Canada.