Graves, Arthur H. Connecticut Agricultural Experiment Station, New Haven, Connecticut.
Davis, Kenneth P. School of Forestry, Yale University, New Haven, Connecticut.
Last reviewed:January 2020
- Other species
- Plant pathology
- Related Primary Literature
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Any species of Ulmus, a genus of hardwood trees in the Northern Hemisphere, with simple, serrate, deciduous leaves. The American or white elm (U. americana) is the most important species (Fig. 1). It is a large, typically vase-shaped tree that usually grows to about 80 ft (24 m) but may reach a height of 140 ft (43 m). The leaves are unequal at the base and doubly serrate; that is, the leaf teeth are themselves toothed. The winter buds are brown, scaly, and usually at one side of the leaf scar. The fruit, ripening in late spring, is a small, flat, winged, elliptical samara, fringed with hairs on the edge (Fig. 2a).
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