Virginia Tech Dendrology

hardy rubber tree Eucommiaceae Eucommia ulmoides Oliv. symbol:
Leaf: Alternate, simple, ovate to elliptical, 3 to 6 inches long, 1 to 3 inches wide, margin sharply serrate, base rounded to wedge shaped, long acuminate tip; conspicuously shiny green above, a bit paler but still glossy below, sunken veins; when torn, fine silk-like gum strands hold the pieces together.
Flower: Species is dioecious; inconspicuous, solitary (male flowers in crowded groups), greenish-brown, 1/2 inch long, appearing with the leaves in early spring.
Fruit: Oval flat, elongated, wafer-like samaras, 1 inch long, ½ inch wide, notched at apex; initially pale green but turning brown when ripe in late summer to early fall.
Twig: Slender to moderate, gray brown; buds are small, pointed, shiny reddish brown; false end bud.
Bark: Shallowly, criss-crossing ridged and furrowed, gray brown.
Form: A medium sized tree to 60 feet with a rounded, dense crown, nearly as wide as it is tall.
Looks like: American elm - white mulberry

Additional Range Information: Eucommia ulmoides is planted in the USDA hardiness zones shown above and is not known to widely escape cultivaton. Download the full-size PDF map.
External Links: - Horticulture Information
All material 2025 Virginia Tech Dept. of Forest Resources and Environmental Conservation; Photos and text by: John Seiler, Edward Jensen, Alex Niemiera, and John Peterson; Silvics reprinted from Ag Handbook 654; range map source information