On a sunny afternoon, the leaves of a ginkgo take on a ravishing range of golden tones. The only tree with truly fan shaped leaves, they flutter and twist but, at the moment, hold fast to their branches. When the time comes, all those little yellow fans seem to come to a remarkable agreement. It’s not unusual to pass a gold-crowned tree one morning and then, within a day or two, discover those leaves forming a bright carpet under the nearly-bare tree. Ginkgos can be unusually decisive.