EUCOMMIALES

order of dicotyledonous flowering plants comprising the single species Eucommia ulmoides (family Eucommiaceae). It is an elmlike tree of central and eastern China notable as a woody plant of temperate regions with milky latex from which rubber can be produced. Eucommia is cultivated as an ornamental in mild climates. The bark has medicinal properties and is valued especially by the Chinese. The species is also of interest for its isolated evolutionary position, as reflected in the status it holds as a single-species order. No other plant orders quite encompass the characteristics of this plant, although it has been referred to the witch hazel and nettle orders (Hamamelidales and Urticales) by different authorities. In addition to latex and deciduous leaves, the order is characterized by the presence of simple, toothed leaves produced alternately along the stems. The flowers are solitary and unisexual and lack petals and sepals. The male flowers have 6 to 10 stamens (pollen-producing structures), and the female flowers have one ovary composed of two carpels, one of which aborts during development. The fruit thus contains only one seed and is a dry, winged structure.