Deciduous shrubs or small trees with bitter bark, usually alternate trifoliolate or pinnate leaves with pellucid dots, cymose inconspicuous yellowish green flowers, and orbicular winged fruits. Flowers polygamous. Calyx 4- or 5-partite, lobes imbricate. Petals 4 or 5, much longer than the calyx. Stamens 4 or 5. Ovary 2- or 3-celled, with 2 ovules in each cell. There are six species, from temperate North America. is the Greek name of Ulmus campestris, which like this has winged fruits.

1. P. trifoliata. Hop-tree. - A small tree of no special merit, with trifoliolate glabrous yellowish green leaves on long-petioles; leaflets ovate, obscurely crenate. The leaves and fruits when bruised emit a powerful odour resembling hops. There is a variegated variety.

Phellodendron Amurense is a small hardy tree from North-eastern Asia, with opposite or alternate unequally pinnate eglandular leaves and inconspicuous dioecious flowers.