I've seen some mentions online that they are, and that the stems taste like raw green beans. Here are a few links I've found:
- http://answers.yahoo.com/question/index?qid=20100808065042AA91qGE
- http://alloveralbany.com/archive/2008/05/09/tulips-really-are-edible-sort-of
One thing that worries me is the "deadly fungus" (that the first link mentions) which grows around decaying bulbs.