The annual signature of the roots of relatively few species of North American herbaceous perennials is known, which is unfortunate, considering the potential contributions an increased understanding of age structure of populations of such species could represent. To help fill this gap, we briefly communicate here results of recent work on Echinacea laevigata and E. pallida (Asteraceae, Heliantheae), both species of conservation concern in the eastern United States. Analysis of cross-sections of individuals of known age of both species revealed an annual signature consistent with that reported for other herbaceous perennials, namely the development of clusters of vessels with conspicuously large diameters, marking annual spring root growth, followed by vessels of reduced diameter in the remainder of the year.