rock elm Ulmaceae Ulmus thomasii
Leaf:Alternate, simple, elliptical ovate, 2 1/2 to 4 inches in length, doubly serrated, base inequilateral, dark green and smooth above, paler and somewhat downy beneath.
Flower:Species is monoecious; in short, tight hanging clusters, reddish-green in color, appearing in early spring before leaves.
Fruit:Thin wafer-like samara, oval to obovate in shape, slightly pubescent, 1/2 inch long, mature in spring.
Twig:Slender, zigzag, reddish brown, often (when rapidly growing) developing irregular corky ridges after a year or two; buds ovate, reddish brown, similar to American elm, but more slender.
Bark:Deeply furrowed, flattened ridges, interlacing, grayish brown in color, similar to American elm but no conspicuous layers in bark cross sections.
Form:Medium sized tree reaching heights of 70 to 80 feet with a narrower, more upright crown than American elm.