Ligustrum sinense Lour. is a shrub native primarily to China, and has been introduced into several areas of the world. In southeastern United States, it grows with the native shrub Forestiera ligustrina (Michx.) Pour. The present study compared the branch architecture, leaf characteristics, reproduction, and phenology of the two species to identify aspects that might influence the invasiveness of L. sinense. Both species were sampled along the woodland edges of cedar (limestone) glades (1362 79 mmol m-2 s-1, clear day at noon in August) and in the (mostly) redcedar forest (112 13 mmol m-2 s-1) in middle Tennessee between March 2000 and February 2001. Multivariate analyses of variances (MANOVAs, P 0.05) indicated significant differences between the species. Regardless of the habitat, L. sinense had higher stem elongation rate, leaf weight ratio, leaf area ratio, and number of fruits per branch, had lower leaf abscission rate and percentage of insect-damaged leaves, and a more tree-like growth form than F. ligustrina. Leaf area expansion rate, leaf area, and height of L. sinense growing in the woods were greater than those of L. sinense growing along the glade and greater than those of F. ligustrina in both habitats. Branch architecture based on branch length and orientation and on bifurcation ratio was similar between the species. However, leaves of L. sinense in both habitats and those of F. ligustrina in the woods were oriented at 98-107 from vertical but those of F. ligustrina along the glade were at 132. The results suggest that L. sinense has a competitive advantage over F. ligustrina due to its greater ability to spatially and temporally capture light, particularly in response to the light environment, and its higher fruit production.

Key words: exotic species, Forestiera, invasibility, Ligustrum, Oleaceae