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THE MICHIGAN BOTANIST
Vol. 41
The discovery of Eucommia ulmoides as an escape is not necessarily an indication that the species will become invasive. In fact, the species is planted relatively infrequently, and since this is the first report of its escape in the more than
100 years since its introduction in the United States, it seems unlikely that it will
become invasive. Hardy rubber-tree does not fit the profile of readily invasive
species as described by Reichard & Hamilton (1997). Studies by Call & Dilcher
(1997) of the aerodynamics of Eucommia fruits showed that they are dispersed
in a downward spiral with an increasing lateral component. The fruits are relatively heavy and not as easily wind-blown as are samaras of other, more invasive
woody plants, such as Ulmus species (Anonymous 2002; Sherman-Broyles et al.
1997). If more escapes of this species are to be found, it will likely be in the
vicinity of pistillate trees near fence rows and woodlots.
LITERATURE CITED
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Barker, P.A. 1984. Eucommia ulmoides: a tree for urban areas. Journal of Arboriculture 10: 233-235.
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Gilman, E.F. & D.G. Watson. 1993. Eucommia ulmoides-Hardy Rubber Tree. Environmental Horticulture Department, Florida Cooperative Extension Service, Institute of Food and Agricultural
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Hutchinson, J. 1967. The Genera of Flowering Plants (Angiospermae). Clarendon Press, Oxford. 2
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Li, Y., T. Sato, K. Metori, K. Koike, Q.M. Che, & S. Takahashi. 1998. The promoting effects of geniposidic acid and aucubin in Eucommia ulmoides Oliver leaves on collagen synthesis. Biological
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