Understory vegetation of 17 clearcuts 1 to 26 years old and three mature secondary forests in Garrett County, Maryland was sampled during the summer to investigate species composition and abundance during forest regeneration. Canonical correspondence analysis (CCA) was used to determine which measured environmental variables (EVs) were significantly related to species distributions among the sites and to characterize species abundances along these environmental gradients. Stand age and site moisture were the most important EVs related to species distributions. Biplots of EV vectors and species scores indicated early successional and shade-associated species (e.g. Rubus spp. and Arisaema triphyllum, respectively) that were most abundant in recent clearcuts (<10 yr old) and shade-associated species that were most abundant in older clearcuts and mature stands. Early successional species declined or disappeared as regenerating tree canopies started to close. Species distributions were significantly related to site moisture despite the broad range of light availability associated with differences in stand age and overstory basal area among the study sites.