They were when I was a kid in Michigan, too, but I never saw one. They don't grow around here...little does that isn't cactus. 
I remember seeing a trillium in middle school as part of a field trip to the local vocational center. We did a nature hike and I remember the man telling me that they only bloom once every two years. That was two decades ago at this point. I'm honestly surprised I hadn't seen one in bloom since then, because I've walked that trail almost every day for years now.
