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.
Evergreen trees or shrubs, often with two kinds of leaves, and usually dioecious flowers. Leaves needle-shaped, linear or lanceolate, rigid or flexible, scattered or imbricated, not clustered. Male flowers in small axillary clustered aments. Fruit small, berry-like, composed of a few closely appressed at length fleshy scales with 1 or more seeds at the base of each scale. This genus is very numerous in species and forms which are very difficult of discrimination, and it is almost impossible to determine them from the most carefully framed descriptions, much less from the short notes we are able to afford space for. But those who are familiar with some of the species may glean from our comparative characters what the others are like. The species are all natives of temperate and cold regions, mainly in the north. The classical name for the common species.
1. J. Chinensis. - This is a very handsome dioecious shrub. The male and female plants are of distinct habit and aspect, the former being the handsomer of the two. Leaves ternate or opposite, linear, flat, acute and spreading, or small, scale-like and closely imbricated. On young plants and in the males they are nearly all of the first sort. The male plant is more universally cultivated than the female. It is a dense much-branched shrub with dark green foliage and somewhat drooping branches. The flowers are produced in great abundance in early Spring. The male plant bears the alias of J. flagelli-fdrmis, and has long pendulous branches of a glaucous hue. Native of China and Japan, and quite hardy.
2. J, Japonica, syn. J. procumbens. - A dwarf dense bushy evergreen, very similar to the last in foliage, which is however of a bright lively green. A desirable hardy shrub from China and Japan.
3. J. communis. Common Juniper. - This is the only indigenous species, and one of wide distribution, occurring throughout Europe, North Africa, North Asia, and northern parts of North America, in a great variety of forms, from a tree 50 feet high to a creeping bush not more than a foot high. The leaves are subulate, rigid, sharp-pointed, spreading, and opposite or in threes, usually glaucous above and green below. There are several distinct varieties in cultivation, among which we may mention : - alpina, syn. Canadensis and depressa, of trailing or ascending habit and glaucous foliage; Hibernica, Irish Juniper, a distinct variety of erect dense conical outline and silvery foliage; Hibernica variegata, the same as the last with prettily variegated leaves; Suecica, Swedish Juniper, a more erect-growing form than the type, with longer more distant leaves of a yellowish-green tint; and pendula, with slender somewhat drooping branches of a reddish colour, contrasting well with the glaucous green foliage. J. compressa is a sub-variety of the Irish Juniper, of dwarfer denser habit, with slender branches and smaller leaves.
4. J. Virginiana. Red Cedar. - A shrub or small tree occasionally attaining a height of 30 feet or more. Leaves on young plants and some parts of the older subulate and spreading; on older, nearly all very minute, scale-like and closely imbricated. Fruit very small, of a bluish glaucous tinge. This is an extremely variable species both in size, habit and foliage, and some of the forms rank amongst the hardiest and most ornamental of the genus. From the great disparity in the proportion of scale-like leaves and subulate leaves in different individuals, as well as the more or less distinct habit, it is difficult to find two plants exactly alike, even in a large plantation. The prevailing hue is dark sombre green, but in the variety glauca, syn. alba avgentea and cinerascens, the foliage is of a silvery glaucous tinge. The compact conical habit of this variety combined with its silvery foliage renders it very distinct and desirable. J. V. humilis is a dwarf spreading form with foliage of a reddish tinge. J. V. pendula, of which there are two or three varieties, has long slender pendulous branches. The variety called pendula viridis is the best. In addition to the above we may mention the variegated varieties aurea and alba of the ordinary form. The Red Cedar is a native of the greater part of the United States.
5. J. thurifera. Frankincense Juniper. - A very ornamental pyramidal tree from 30 to 40 feet high in its native country. Branches slender, numerous, densely clothed with subulate imbricated leaves of a light glaucous green. Fruit large, ovate, dark-coloured, covered with a glaucous bloom. A native of the mountains of Spain and Portugal, and quite hardy in this country,.
6. J. squamata, syn. J. dumosa. Creeping Cedar. - A trailing or drooping densely branched shrub. Branches rather thick. Leaves of a light glaucous green, crowded, linear-subulate, convex below, appressed, persistent, and changing to brown the older branches. This is a very distinct and curious species, native of the mountains of Northern India at a great elevation.
7. J. Sabina. Savin. - A dwarf spreading shrub with numerous reclinate or trailing branches. Leaves small, scale-like, acute, slightly spreading, of a deep dark green colour. Fruit small, purplish, spherical, usually 1-seeded. This shrub was formerly much more extensively cultivated than it is at the present day. Nevertheless a well-grown healthy specimen is by no means devoid of beauty and quite unique in the tabular form it assumes. The variety cupressifolia is said to be perfectly distinct in its slenderer branches and glaucous silvery foliage. J. tamariscifolia, syn. J. Sabinioides, is also a variety; and there is a prettily variegated variety. This species inhabits the mountains of Central and Southern Europe, and also occurs in Canada and other parts of North America.
8. J. prostrata, syn. J. repens. - This is another trailing densely branched species with shining dark green loosely imbricated foliage and small purplish glaucous fruits. A native of North America, well adapted for covering rock-work, etc.
J. densa and J. recvrva are two handsome North Indian species of dwarf habit, but they, like many other species, are very liable to the attacks of the red spider, except in humid localities.
9. J. excelsa of Bieberstein, not of Madden. - In its native habitat this attains a height of 30 or 40 feet, forming a compact densely-branched tree. Leaves small, subulate, acute somewhat spreading, glaucous green. It is a native of the South-east of Europe and Western Asia, and rather tender in this country. J. excelsa of Madden is the J. religiosa of Royle, a tree of considerable size, scarcely known in cultivation.
10. J. fragrans. - An erect pyramidal shrub with very numerous exceedingly slender branches densely clothed with minute scale-like imbricated silvery-green leaves. In young plants and on scattered branches of older ones the leaves are subulate and spreading. This species emits an extremely powerful odour when bruised. It is said to be a native of Northern Europe by some, and by others it is reported to come from the Rocky Mountains in North America, that is to say, if both parties have the same species in view.
11. J. Oxycedrus. Prickly Cedar. - A small loosely branched tree with linear-lanceolate very sharp-pointed light green leaves, and large shining red fruits. A native of the Mediterranean region.
J. macrocarpa, from the same region, is distinguished by its still larger purplish glaucous fruit about 8 or 9 lines in diameter. J. drupacea, from Asia Minor, has the spreading leaves in six rows, and a fleshy fruit about an inch in diameter. J. Bermudiana is a very beautiful though tender species with long linear spreading leaves of a light yellowish-green colour.
12. J. Phoenicea. - A small ornamental tree with loose drooping branches and small imbricated leaves of a light green colour. J. Langoldiana is said to be the male plant of this species. The medium-sized fruit is described as pale yellow when ripe. A native of rocky districts on the shores of the Mediterranean Sea.