Family composed of 8 genera and about 64 species of trees and shrubs, widespread throughout tropical, subtropical and temperate regions of the Northern Hemisphere. In North Africa it is represented by 2 genera, with 1 species each.
Key to genera
1 Flowers in glomeruli on branches of 2 or more years. Fruit a samara. Bark dark brown, very fissured Ulmus
1 Flowers solitary on young branchlets of the current year. Fruit a drupe. Bark whitish-greyish, smooth Celtis
Updated by: A.V. Pérez Latorre.