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.
This vast order furnishes us with very few hardy subjects; in fact, not a single species that will withstand the climate throughout the kingdom. It includes about seventy-five genera and some 2,000 species, all of which are shrubby or arborescent. They are especially abundant in South America and Australia. The Grum-trees (Eucalyptus) of the latter country number nearly 150 species. Some of the slower-growing kinds may prove hardy in this country, but most of them grow so rapidly and make so much wood in one season that it does not ripen, and is cut back by frost. One slow-growing species (E. pulverulenta) was formerly represented in Kew Gardens by a specimen about 30 feet high, which must have weathered several winters. The opposite exstipulate leaves furnished with immersed transparent glands, imbricate calyx-lobes, numerous stamens, and inferior fruit, characterise the great bulk of the order; but Australia produces a distinct tribe or two differing in some particulars.