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.
With the exception of the Common Holly, Box, Portugal Laurel, Magnolia grandinora, Evergreen Oak, Strawberry-tree, Sweet Bay, and a few others, this class is mainly furnished by one family, the Coniferae.
Thus it will be seen that we are almost entirely dependent upon the deciduous class for trees bearing conspicuous flowers. Evergreen trees possess little that is attractive either in flower or fruit; but by way of compensation, the foliage of many species is very ornamental, and in habit they are unsurpassed for dignity and grace. We do not forget the bright scarlet berries of the Holly, and the handsome cones of some of the Firs and Cedars; but the former is oftener seen as a bush, and fruiting Conifers, with the exception of a few species, are still rare in this country. Although planters have now a very large number of species to select from, comparatively few of them have attained their full development with us, and therefore we are unable to judge of their value for permanent plantations. Many of them that are exceedingly beautiful when young, become unsightly as they rise above the dimensions of a shrub, and this, in many instances, may be ascribed either to uncongenial soil, defective planting, or exposure to bleak winds. The Yew, Cedar of Lebanon, Deodar Cedar, Norway Spruce Fir, Silver Fir, Mammoth Tree, Red Cedar, Austrian Pine, Pinaster, Pinus excelsa, P. insignis, P. Benthamiana, Picea, Pinsapo, P. Nordmanniana, P. nobilis, etc., Abies Douglasii, A. Canadensis, Araucaria imbricata, Cryptomeria Japonica, and several others, are known to be hardy. But several of these are impatient of a wet, heavy soil, whilst others will not flourish in an exposed situation. The question of suitability of soil and situation forms the subject of another paragraph.
Variegation in large evergreen trees - if we except the silvery bands on the leaves of many Conifers, which may be termed natural variegation - is almost unknown. There is, however, a variety of Cryptomeria Japonica beauifully variegated with yellow, a silvery variety of the Spruce Fir, and gold and silver varieties of Cupressus Lawsoniana; and perhaps the most beautiful are the gold and silver variegated Yews J but the latter are better referred to the shrubby class. Variegated Hollies 20 to 30 feet or more high are occasionally seen, but as a rule they do not exceed the dimensions of a shrub.
Weeping forms in the true sense of the word, as applied to the Weeping Ash, Elm, Beech, etc., are scarcely represented. Some, like a variety of the Silver Fir, have depressed branches. The varieties of Biota, Taxus, etc., with pendulous branches are more properly referred to the frutescent class.