H. SCANDENS.--Climbing Hydrangea. j.a.pan, 1879. This is not very hardy, but with the protection of a sunny wall it grows freely.
The Hydrangeas require a rich, loamy soil, and, unless in maritime districts, a warm and sheltered situation. They are readily propagated by means of cuttings.
HYMENANTHERA.
HYMENANTHERA CRa.s.sIFOLIA.--A curious New Zealand shrub with rigid ashy-coloured branches, and small leathery leaves. The flowers are violet-like in colour, but by no means conspicuous. The small white berries which succeed the flowers are, in autumn, particularly attractive, and very ornamental. It is perfectly hardy and of free growth in light peaty earth.
HYPERIc.u.m.
HYPERIc.u.m ANDROSAEMUM.--Tutsan, or Sweet Amber. Europe (Britain). A pretty native species, growing about 2 feet high, with ovate leaves having glandular dots and terminal cl.u.s.tered cymes of yellow flowers.
H. AUREUM.--South Carolina and Georgia, 1882. This soon forms a neat and handsome plant. The flowers are unusually large, and remarkable for the tufts of golden-yellow stamens with which they are furnished.
H. CALYCINUM.--Aaron"s Beard, or Rose of Sharon. South-east Europe. This is a well-known native species of shrubby growth, bearing large yellow flowers from 3 inches to 4 inches in diameter. It is a prostrate plant, with coriaceous glossy leaves with small pellucid dots, and of great value for planting in the shade.
H. ELATUM is a spreading species from North America (1762), growing to fully 4 feet in height, and bearing terminal corymbs of large, bright yellow flowers in July and August. Leaves rather large, oblong-ovate, and revolute. On account of its spreading rapidly from the root, this species requires to be planted where it will have plenty of room.
H. HIRCINUM.--Goat-scented St. John"s Wort. Mediterranean region, 1640.
A small-growing and slender species, with oblong-lanceolate leaves 2 inches long, and producing small yellow flowers in terminal heads. There is a smaller growing form known as H. hircinum minus. The plant emits a peculiar goat-like odour.
H. MOSERIANUM is a beautiful hybrid form with red anthers.
H. OBLONGIFOLIUM (_syns H. Hookerianum_ and _H. nepalensis_).--Nepaul, 1823. An evergreen species, about 4 feet high, with oblong, pellucid, dotted leaves, and deep golden, somewhat waxy flowers at the end of summer.
H. PROLIFIc.u.m.--North America, 1758. This is a much branched twiggy shrub, about 4 feet high, with small, linear-lanceolate leaves, thickly studded with pellucid dots. Flowers not very large, five-petalled, and of a pleasing bright yellow colour. The allied if not identical H.
Kalmiana is worthy of being included in a selection of these plants.
H. URALUM.--Nepaul, 1823. A neat but fragile species that attains to about a yard in height. Leaves rather small, elliptic, almost stalkless, and perforated with transparent dots. Flowers small and of a bright golden yellow.
H. fasciculatum, H. pyrimidatum, and H. patulum are all worthy of attention, where a good representative collection is of importance. The Hyperic.u.ms succeed best when planted in a rather sandy and not too dry loam, and they are readily increased either from divisions or by means of cuttings.
IDESIA.
IDESIA POLYCARPA (_syns Flacourtica j.a.ponica_ and _Polycarpa Maximowiczii_).--A j.a.panese tree of small growth, and only introduced to this country in 1866. It is a handsome, hardy species, bearing large, bright-green leaves with conspicuous crimson footstalks, often 4 inches across, and of a glaucous tint on the under sides. The deliciously fragrant flowers are greenish-white or yellowish-green, and produced in graceful drooping racemes. In southern England it does well, and, being a tree of unusual beauty of both leaves and flowers, is well worthy of attention. Rich loam, not too stiff, will grow the Idesia well.
ILEX.
ILEX AQUIFOLIUM.--Common Holly. Europe (Britain) and West Asia. Though the Hollies are not usually reckoned ornamental for the sake of their flowers, their berries are highly so. Some of them are nevertheless deliciously fragrant when in bloom. The leaves of this, our native species, in their typical form are oblong-ovate, wavy, and deeply spiny-toothed. The tree flowers in May and June, while the cl.u.s.ters of bright red berries ripen in autumn, persist all the winter, and sometimes even hang on tree till a second crop is matured, provided they are not devoured by birds during severe weather. The varieties are very numerous, and differ chiefly in the form and toothing of the leaves, which are variegated in many cases, their size and form, and in the colour of the berries in a few instances.
I. Aquifolium albo-marginata has ovate, nearly flat, spiny-serrate leaves, with a narrow silvery margin, and fruits freely. I. Aquifolium fructu albo has white berries; in I. Aquifolium fructu luteo they are yellow and very abundantly produced; and in I. Aquifolium fructu nigro they are black. I. Aquifolium handsworthensis has elliptic-oblong spiny leaves, with a creamy-white margin and marbled with gray. Grafted trees bear berries in great profusion from the time they are only a foot high, and are highly ornamental. I. Aquifolium Hodginsii has large, broadly oblong-ovate, slightly spiny leaves, and large crimson-red berries that ripen late in autumn. I. Aquifolium Hodginsii aurea is a sub-variety with a broad golden margin to the leaves, and the disc splashed with gray. Beautiful and distinct is I. Aquifolium Lawsoniana, with ovate, flat, almost spineless leaves, heavily and irregularly blotched with yellow in the centre. The berries are of a brilliant red. The variety differs from Milkmaid in having flat, nearly entire leaves. I.
Aquifolium pendula has a wide, rounded, drooping head, but otherwise does not differ from the type. Many others bear berries, but the above are all very distinct forms.
I. OPACA.--American Holly. United States, 1744. The leaves of this species are oblong or oval, small, spiny-serrate, and of a dark opaque green. The berries, which ripen in autumn, are small, bright red, and very liable to be eaten by birds. In America this Holly is put to precisely the same purposes as the common Holly is in Europe. It is perfectly hardy here.
ILLICIUM.
ILLICIUM FLORIDANUM, from Florida (1771), is a beautiful but uncommon shrub, probably on account of its being tender and susceptible to injury by frost, unless in the warmer and more favoured parts of the country.
The fragrant flowers are of a purplish-rose, while the foliage is neat and of a pleasing green.
I. ANISATUM (_syn I. religiosum_), from China and j.a.pan (1842), is too tender for outdoor culture in this country.
INDIGOFERA.
INIDGOFERA GERARDIANA (_syns I. floribunda_ and _I. Dosua_).--India, 1842. This forms a compact dwarf bush in the open, but is still better suited for covering a wall, the growth and floriferousness being then much increased. The foliage is neat and Pea-green, while the bright pink Pea-like flowers are produced in long racemes. It is a pretty bush, and grows freely enough in any good garden soil, but very fine flowering specimens may be seen in light, sandy soil of a peaty nature. There is a white flowered variety named I. Gerardiana alba.
ITEA.
ITEA VIRGINICA.--North America, 1744. This is a neat, deciduous shrub of 3 feet or 4 feet in height. The ovate-lanceolate leaves are of a light greyish-green, and the small white flowers are produced in dense racemes or spikes. Planted in a somewhat shady place, and in rather cool, damp soil, this little shrub does well and flowers profusely.
JAMESIA.
JAMESIA AMERICANA.--Rocky Mountains and Colorado, 1865. Amongst early spring-flowering shrubs this pretty but neglected plant is one of the best, of perfect hardihood, for it stands the vigour of our winters with impunity, and of dense thick growth; it is suitable for using in a variety of ways, as well as for purely ornamental purposes. The leaves are oval and neatly dentated, and the flowers individually of large size, pure white, and produced in terminal bunches. Cool soil and a shady situation would seem to suit the plant admirably, but for screen purposes in the rock garden or border it is invaluable on account of the strong and dense twigs.
JASMINUM.
JASMINUM FRUTICANS.--South Europe, 1570. An evergreen species, well adapted, from its rather stiff and upright growth, for planting alone.
It has trifoliolate leaves and showy yellow flowers.
J. HUMILE.--India, 1656. A hardy species of dwarf growth, and bearing beautiful golden flowers produced in summer.
J. NUDIFLORUM.--Naked Jasmine. China, 1844. A showy and well-known species, from China, with numerous, usually solitary yellow flowers, ternate leaves, and flexible branches. The variety J. nudiflorum aureo-variegatum has golden-variegated leaves.
J. OFFICINALE.--Northern India to Persia, 1548. The white-flowered Jasmine of our gardens is a very beautiful and desirable clambering shrub, either for wall covering, for planting by tree stumps, rooteries, or rockeries, or for screening and draping the pergola or garden latticework. From its great hardihood, vigour of growth, and beauty of flowers, it is certainly one of the most deservedly popular of wall shrubs. The branches are deep green, angular, and flexible, the leaves pinnate, and the flowers pure-white and sweetly-scented. The variety J.
officinale affine has flowers that are individually larger than those of the species; J. officinale aurea has badly variegated leaves; J.
officinale grandiflorum and J. officinale grandiflorum majus, are also desirable kinds.
J. PUBIGERUM GLABRUM (_syn J. Wallichianum_), from North-west India, is not well-known, being tender in most parts of the country.
J. REVOLUTUM.--India, 1812. This has persistent dark, glossy-green leaves, and fragrant, bright yellow flowers, produced in large, terminal cl.u.s.ters. From India, but perfectly hardy as a wall plant, and for which purpose, with its bright evergreen leaves, it is well suited.
As regards soil, the Jasmines are very accommodating, and are propagated by layers or cuttings.
KADSURA.
KADSURA j.a.pONICA.--j.a.pan, 1846. This is a small-growing shrub, with lanceolate and pointed leaves, that are remotely dentated. The flowers are not very showy, being of a yellowish-white colour and about an inch across. They are produced both terminal and axillary, and in fair abundance. The scarlet fruits are arranged in cl.u.s.ters, and when fully ripe are both showy and interesting. Generally speaking this shrub suffers from severe frost, but as only the branch tips are injured, it shoots freely from the stock. It produces its flowers in the autumn.
There is a variety with variegated leaves.