One of the most iconic native North American trees is the eastern redbud (Cercis canadensis). This tree is one of the earlier flowering forest trees in the spring. Because it is beautiful when in flower, it has become a widespread ornamental tree in the USA and elsewhere around the world. We are interested in answering the following two questions: 1) When do eastern redbud trees flower and fruit across the tree's range and how does the timing of these events vary with location (latitude and longitude) and elevation above sea level? 2) Has the timing of flowering and fruiting advanced in recent years?