This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Trees or shrubs with very hard wood, alternate entire exstipulate leaves, and dioecious polygamous or rarely perfect regular flowers, solitary or cymose in the axils. Calyx inferior, 3-7-lobed, commonly accrescent and persistent. Corolla gamopetalous, deciduous, 3-7-lobed, the lobes usually convolute in the bud. Stamens 2-4 times as many as the lobes of the corolla in the sterile flowers, and inserted on its tube, usually some imperfect ones in the pistillate flowers; filaments short; anthers introrse, narrow, erect. Disk none. Ovary superior, several-celled, in the staminate flowers rudimentary or none; ovules 1-3 in each cavity, suspended; styles 2-8, distinct, or united below; stigmas terminal, sometimes 2-parted. Fruit a berry, containing several seeds, or but one. Seeds oblong, compressed or globose, the testa bony; endosperm copious, cartilaginous; embryo small, usually straight; cotyledons large, foliaceous.
About 6 genera and 275 species, mostly of tropical distribution.