Evaluating the definition and distribution of spring ephemeral wildflowers in eastern North America.

Spring ephemeral phenology is an important shade-avoidance strategy for a large segment of the total understory species in temperate deciduous forests. In North America, the strategy is relatively most important for forest understories at mid latitudes. The definitions of spring ephemerality we provide here serve as an important ecological context for conservation priorities and to evaluate responses of this biodiverse group to future environmental change.