People go nuts over beanie babies, truffles, basketball – and flowers. Tulips, for instance, have made men crazy and caused economic crises. In this hour of To the Best of Our Knowledge, stories of floral obsessions: a tulip-o-maniac and an orchid smuggler. Also, edible vaccines – no more needles, just eat your greens. And, an excursion into the rotting world of fungus.

Susan Orlean writes for The New Yorker and is the author of "The Orchid Thief." She tells Jim Fleming about the brisk trade in endangered orchids; tries to explain why orchids seem to inspire obsession among their collectors; and talks about some infamous orchid collectors. Also, botanist Barbara Ertter tells Judith Strasser that there are many plant species left in North America which haven't been discovered and named yet, and that you don't have to be a specialist to find them. Ertter is Curator of Western North American Flora at the University and Jepson Herbaria at the University of California, Berkeley.

Anna Pavord is a self-confessed tulipomaniac, gardening correspondent for the London Independent and author of "The Tulip: The Flower That Has Made Men Mad." She talks with Judith Strasser about the social history of this common spring flower, which caused people to bankrupt themselves collecting bulbs in the seventeenth century and is still a significant factor in Holland's economy.

Edible vaccines are the latest thing in genetic engineering. Plant pathologist Tom German tells Jim Fleming how food can replace the hypodermic for delivering vaccines. Also, George Hudler (who teaches plant pathology at Cornell) is a man who loves fungus. He tells Steve Paulson some of the marvelous things fungi do for us, from garnishing pizza to recycling garbage. Hudler's book is "Magical Mushrooms, Mischievous Molds."

Distribution dates:

• week of 02/07/99 - hour 2