A small, mainly northern hemisphere family of trees, represented by only four genera in West Africa, all of them also present in a large part of the rest of tropical Africa. Only two species extend to Gambia. No introductions have been made.

Members of the family may be recognised by their simple, alternate stipulate leaves which are ± asymmetrical, pinnately nerved or three-nerved at the base. Flowers are very small, apetalous, ♂, ♀ or, in small axillary inflorescences. The two styles persist on the fruit whether this is a samara or a drupe.

Chaetacme aristata, a small southern savanna tree (Côte d'lvoire eastwards), is readily recognisable by the nodal prickles accompanying the leaf and axillary branch. Its dark-green leathery leaves end in a tiny spine, the produced midrib, and the large stipular hood leaves an encircling scar on the main axis, cf. Chapter 17, Moraceae.

Flowers ⊕ ♂, ♀ or, nearly always monoecious, 4–8 part. K(4–5–8) (free in Celtis), imbricate in Celtis and Holoptelea and ♂ and flowers of Trema and Chaetacme, valvate with the margins folded in (induplicate-valvate) in ♂ flowers of Trema and Chaetacme. CO. A as many as, and opposite, the sepals, episepalous, introrse (except Celtis). G(2) 2-celled (1-celled by abortion), with an apical ovule per cell; the 2 styles are ± branched, divergent, in the adaxial–abaxial plane of the flower, ± a pistillode in – flowers.