This section is from the book "Handbook Of Hardy Trees, Shrubs, And Herbaceous Plants", by W. Botting Hemsley. Also available from Amazon: Handbook of hardy trees, shrubs, and herbaceous plants.
Erect or climbing shrubs or trees, very rarely herbaceous, often clothed with a stellate pubescence, occasionally armed with spines. Leaves alternate, or very rarely opposite, entire, toothed, lobed, or palmately or pinnately divided; stipules various, rarely none. Flowers hermaphrodite or unisexual, regular, usually small, capitate, umbellate, racemose or paniculate. Calyx-tube adnate to the ovary; limb small. Petals 3 or more, often 5, usually valvate. Stamens of the same number, rarely more. Fruit inferior, drupaceous or baccate, 1- or more celled; cells 1-seeded. Very near the Umbelliferae in structure. The species are estimated at about 350, distributed into 35 genera. They are chiefly from tropical countries, but there are a few hardy species familiar in our gardens.