Are Recipes Intellectual Property?

The Food Network has dropped dessert chef Anne Thornton when it was discovered that recipes in her cookbook were, but for small alterations, the same as those in cookbooks by others.  The word "plagiarism" is being used for the case.  It is, at first glance, an odd fit.

Plagiarism generally involves unattributed use of others' ideas or words in a work where it is assumed to be the author's.  Do we have that expectation in a cookbook?  When I read the little paragraph before a recipe, there is always something like "this has been in my family for generations and I grew up loving it..." or "with a couple minor changes, this is a dish I ate at a friend's party..."  Recipes we make, in almost all cases, are not devised out of thin air, but are the result of having had something we liked, figuring out how to make it and writing it down.  When I buy someone's cookbook, I don't think that these were thought up by the author, but that the author is vouching for their quality. 

At the same time, if one is a writer of cookbooks, the recipes are your life's blood.  If someone steals your recipes, they steal your content.  But is it the individual recipes or the range covered in your book that is important?

Can a cookbook recipe be plagiarized?