THE ELM FAMILY (Ulmaceae)

This is a family of mainly deciduous trees, rarely shrubs growing mainly in temperate zones of the northern hemisphere. Elms first appeared in the Miocene geological period about 20 million years ago, originating in what is now central Asia. They are components of many kinds of natural forests; during the 19th and early 20th centuries, many species and cultivars were also planted as ornamental street, garden, and park trees in Europe, North America, and parts of the Southern Hemisphere. Some individual elms reached great size and age. However, in recent decades, most mature elms of European or North American origin have died from Dutch elm disease, caused by a microfungus dispersed by bark beetles. In response, disease-resistant cultivars have been developed, capable of restoring the elm to forestry and landscaping.

Leaves are usually alternately arranged on the stems. The leaf blades are simple (not compound), pinnate, with entire (smooth) or variously toothed margins, and often have an asymmetrical base. The flowers are small, wind pollinated and either bisexual or unisexual. The fruit is a samara (winged seed), nut, or drupe (berry with single pit or stone).

(source: Wikipedia)