Ulmaceae
The Ulmaceae () are a family of flowering plants that includes the elms (genus "Ulmus"), and the zelkovas (genus "Zelkova"). Members of the family are widely distributed throughout the north temperate zone, and have a scattered distribution elsewhere except for Australasia. The family was formerly sometimes treated to include the hackberries, ("Celtis" and allies), but analysis by the Angiosperm Phylogeny Group members suggests that these genera are better placed in the related family Cannabaceae. The circumscription included in the taxobox is the one suggested by P. Stevens on his Missouri Botanical Garden Angiosperm Phylogeny Website and includes information from the  Royal Botanic Gardens, Kew Vascular Plant Families and Genera list. It generally is considered to include ca 7 genera and about 45 species. Some classifications also include the genus "Ampelocera". Description. The family is a group of evergreen or deciduous trees and shrubs with mucilaginous substances in leaf and bark tissue. Leaves are usually alternate on the stems. The leaf blades are simple (not compound), with entire (smooth) or variously toothed margins, and often have an asymmetrical base. The flowers are small and either bisexual or unisexual. The fruit is an indehiscent samara, nut, or drupe. "Ulmus" provides important timber  trees mostly for furniture, and "U. rubra", the slippery elm, is a medicinal plant known for the demulcent property of its inner bark. "Planera aquatica" is also a timber species. "Planera", "Ulmus", and "Zelkova" are all grown as ornamental trees. Phylogeny. Modern molecular phylogenetics suggest the following relationships: