Robert Lee Riffle (1940 2006) was an internationally recognized authority on palms and tropical plants. His landmark book, "The Tropical Look: An Encyclopedia of Dramatic Landscape Plants" (1998), won an American Horticultural Society Book Award, as did "An Encyclopedia of Cultivated Palms" (2003), which he co-wrote with Paul Craft. For 25 years Bob was a strong presence online, answering questions and encouraging gardeners in their endeavors via postings on garden and plant message boards. He generously shared his extensive knowledge gently and with wit as the moderator of the International P...