This tree from southeast China and Korea is naturalized at a few sites in eastern states, from New England to the mid-west (K). A possibly self-seeded tree was discovered in 2012 by M. Canfield and D. Leonard (pers. comm.), growing along a fencerow behind a junkyard in Lexington (FAYE). Tetradium is close to Phellodendron (Flora of China Vol. 11), which differs in its axillary buds concealed within petiole bases (versus exposed), its 5-merous flowers (versus 4-5), and its fused carpels forming a purplish-black drupaceous berry (versus just connate at base, forming a reddish-black fruit of 1-5 follicles). Also, Phellodendron has deeper yellowish inner bark, dark purplish branchlets (versus green), and larger trees develop more thick, corky bark. Both T. daniellii and P. amurense are potentially invasive in much of North America (e.g. Morgan & Borysiewisz 2012; see also Invasive Plant notes at dcnr.state.pa.us), and they should not be used in most horticulture. They are chemically defended from generalist herbivores, and may become especially successful where deer are dense. Without flowers or fruits, both genera are easily confused with Fraxinus; unlike Fraxinus, their buds have pinnate microphyllous scales rather than simple protective scales with differentiated glands or pubesence.