In my elementary school program about Michigan trees, one of the activities is to look at leaf samples and categorize them as needle-leafs or broad-leafs. I can tell almost instantly when a group of students has discovered the Bladdernut.
Either one member of the group will yell out the word "Bladdernut!" and they all start giggling, or the students will begin whispering and pointing and just have to show the word to members of another group.
So what did the poor Bladdernut do to deserve this reaction?