This is winter jasmine on the Swarthmore College campus yesterday. Even this lovely place looks dreary in mud season. Besides the jasmine, we did see a few crocuses, snowdrops, hellebores and attractive containers planted with evergreens. They were a comforting sight after a provocative, alarming and to me, somewhat depressing, lecture by Peter Raven. He's the 2009 recipient of the Scott Medal, an annual prize, along with $12,000, that's awarded by the college's Scott Arboretum to "heroes of the planet." As head of the Missouri Botanical Garden for almost four decades, Raven's passionate cause is to preserve endangered plants and from the sound of it, he was a strong voice for sustainability long before it became every PR person's buzz word. He truly was inspiring. His C.V. is so long, I can't begin to replicate it here, but he was honored yesterday as all medal winners are, for "promoting a greater love of nature...and for spreading the gospel of better planting and design." In the big world out there, he's a champion of biodiversity and plant conservation, and he sounds a rational alarm against needless development, overconsumption and ignorance. I loved how he put this. Biodiversity, he said, "depends on what each of us does, every choice, every day, every place, every one of us." Taking care of this earth is everyone's responsibility, not some obtuse intellectual construct, and it extends right down to what we plant in our back yards, how we live our lives, how big a carbon footprint we leave and how much stuff we buy. Raven ended with a quote from Gandhi that brought a sobered audience to its feet: "The world provides enough to satisfy every man's need but not every man's greed." You can say that again.