The elm family has representatives of 2 genera in our area. The elms (Ulmus genus) are deciduous trees with gray, vertically ridged bark. The simple, alternate leaves are double-toothed and have an unequal (asymmetrical) base. The small inconspicuous green flowers are in clusters along twigs. The fruit is a 1-seeded nutlet surrounded by a papery wing. The hackberries (Celtis genus) are bushes.


The radially symmetrical flowers are usually showy and have 4 sepals and 4 petals. The cross-like stigma is 4-branched. The flowers of the evening primroses proper open toward evening, while sundrops bloom during the day. The simple leaves may be opposite or alternate.