The objective of this study was to describe the biology of Sassafras albidum growing on upland hardwood sites in the Ridge and Valley Physiographic Province of Virginia ln an attempt to better understand how this common understory species becomes a dominant vegetative component following clear-felling. Biomass and leaf area regressions were developed using data collected from stems growing on xeric sites (SI₅₀ < 15.2 m) and mesic sites (SI₅₀ > 18.3 m). Due to strong heteroscedasticity in the data, logarithmic allometric equations were found to be the best fitting models. No significant differences were found between biomass equations from the two site qualities. Leaf area regressions were found to be significantly different. Excavations of the root systems of stumps and residual stems found in clear-felled upland hardwood sites indicated that sassafras has a prominent lateral root system. Roots were between 5 and 15 cm in-depth and contained several sprouts. A comparison of the regeneration origin of sassafras stems growing on two sites with differing available soil moisture suggests that root sprouting was the dominant form of regeneration on dry sites, whereas on most sites root sprouting and seedling origin stem were present in equal amount. Root sprouts were significantly larger in size than seedlings. Sex ratio determinations across four site qualities showed a male biased sex ratio. Although sassafras is reported to be delicious, hermaphroditic flowers were found on all sites. Comparison between male and female plants on each site suggest that males have a slight competitive advantage. / Master of Science