American Elm — Ulmus Americana

Ulmus is from the Saxon ulm, meaning elm; americana refers to America. Elm groves were favorite council sites for many Indian tribes and later became meeting places for treaty talks between Indians and whites. Early settlers often spared elms when they cut down all other trees.

A survey of all historic trees of our country shows that elms outnumber white oak and live oak (its two closest rivals) two to one. Once regarded as the nation’s most prized and widely- planted street tree, the American elm has been decimated by Dutch elm disease with over one million trees lost annually. The tree was popular because of its upright vase shape, ease of establishment and adaptability to a wide variety of soils.

Over planting of this species in many Colorado cities, including Denver, was a tragic mistake. Some cities now suffering severe losses from Dutch elm disease are virtually treeless. Unfortunately, some of these same cities are now making the same mistake by over planting trees such as honeylocust, green ash and silver maple.

It is not easy to distinguish between different elm species by the foliage alone. Most such as American elm, have lopsided, oblong leaves with coarsely and doubly toothed margins. Likewise, the winter buds are lopsided, reddish-brown and sharply pointed. The best way to distinguish American elm from Rock elm (Ulmus is by the growth habit of the tree itself. elm has a typical vase-shape with the upper tending to arch gracefully. Rock elm is and has numerous short, rigid branches.

The fruit of elm is a wafter-like, winged seed that is disseminated by wind in spring. The species is native in every state east of Colorado, Wyoming and New Mexico and has become naturalized in most other states including the western coastal area.

Other Denver locations

The elm is the major street tree in Denver.

http://en.wikipedia.org/wiki/American_Elm