The Encyclopedia Americana (1920)/Plants, Ornamental
PLANTS, Ornamental. The climate and soil of North America vary so tremendously that only by a close study of local florists' catalogues, and the reports of State experiment stations, can the ornamental plants suitable for any given locality be determined. A hint of the trees, shrubs, climbers, aquatics and lesser herbaceous plants, of the perennial type, most frequently set out, is given below.
DECORATIVE PLANTS
Rapidly-growing trees, particularly for
treeless regions, are the cottonwoods (Populus)
common along mid-western water courses; the
silver maple (Acer) and the white willow
(Salix) for moist soils: white and Scotch pines
(Pinus) for sandy ones: white and Norway
spruces (Picea); green ashes (Fraxinus); osage
orange (Toxylon); European larch (Larix);
black locust (Robinia); hardy catalpa {Catalpa)
and Russian mulberry (Morus) are
recommended for planting, serving as windbreaks,
as shade trees and as material for fence posts
and fuel.
For street planting in city and village, certain trees have been found more or less resistant to the deleterious effects of urban existence. The most important of these are the plane-tree of Europe {Platanus) readily identified in winter by its long-hanging balls of fruit; the trim maples (Acer) the leaves of some species turning to gorgeous color in fall; graceful elms (Ulmus) arching over roadways, wherever they can be protected from noxious insects; the tree-of-Heaven (Ailanthus), evil-smelling when in bloom, but gay later with huge bunches of pinkish fruits, half-hidden in the compound foliage of this most enduring of all these trees. Rather less common are the Japanese Gingko, a conifer which sheds its fan-shaped foliage in winter; ashes (Fraxinus) untroubled by insects; shapely lindens (Tilia), fragrant in bloom and humming with nectar-seeking bees, and occasionally other trees like slowly-growing oaks (Quercus) and Liriodendrons. Lombardy poplars (Populus) and bald cypress (Taxodium) are planted for formal gardens; tall, slender and conical they also make good deciduous screens. Coniferous evergreens are planted moreover for screens as well as for windbreaks and ornament, especially the spruces (Picea); pines (Pinus); firs (Abies), and hemlocks (Tsuga). Sombre, thick-foliaged cedars (Juniperus), Chamæcy-paris, and arbor-vitæ (Thuya), lend themselves to architectural effects, being symmetrical of growth; they are frequently set and trimmed for hedges, taking the placed of the old-time slowly-growing yew (Taxus) and box (Buxus). Privet (Ligustrum) is also used much for quickly-growing hedges; also barberries (Berberis) brilliant in autumn with arching sprays loaded with oval scarlet berries; the even more interesting holly (Ilex); thorns (Cratægus), handsome both in flower and fruit; the glossy osage orange (Toxylon), and honey-locust (Gleditsia), the latter being sufficiently armed with spines. Japanese quince (Cydonia), flowering gayly, is used for low hedges. The Southwest has thickets of cactus, impressed for impenetrable spiny hedge-rows.
On lawns and in gardens are planted beeches (Fagus) some varieties having purple leaves; the “silver-vested birch” (Betula) most interesting in its weeping forms; the weeping willows(Salix) and Camperdown elms (Ulmus) with other “weeping” forms of different trees; sumachs (Rhus) holding up their pyramids of scarlet velvety fruit all winter; mountain ash (Sorbus), the rowans of Scotland, attractive to all birds when adorned with its bunches of red berries, and repellant to witches if such be about; honey-locust (Gleditsia) prodigal of thorns, and of heavy pods filled with sweet pulp hanging amid the delicate compound foliage of the flattened top. These are more conspicuous for foliage and form than for their flowers, but there are a number of available flowering trees. That locust (Robinia pseudacacia) called “acacia” in Europe, covers itself with masses of white fragrant pea-blossoms as the compound leaves appear, yielding much honey to bees; even earlier bloom the purple flowers of the Japanese Paulowina, on naked stems, tike those of the Sophora, from the same country, which blooms much later, but is scarcely hardy north of New York; and those of the gay redbud (Cercis). as well as the white tassels of the shadbush (Amelanchier) and the great snowy bracts of dogwood (Cornus). Japan sends some of the most exquisite flowering plums and cherries, scarcely more beautiful, however, and not as fragrant as the native flowering crabs (Pyrus). Yellow wood (Cladrastis), the fringe tree (Chionanthus) and the silver bell tree (Halesia) are native white flowering trees of much value for small places. Indian bean trees (Catalpa) although of Southern origin are frequently seen in Northern parks, where their great panicles of white, streaked, velvety flowers are set off by the huge heart-shaped leaves. The catalpa is apt to be irregular, even sprawling in habit, but the fa- miliar horse-chestnut (Æsculus) and its American relatives the buckeyes, are singularly symmetrical in growth, and the former has striking flower-spires of white.
In warmer climes we find live oaks (Quercus) dripping with Spanish moss; palms — Washington, Royal, Phœnix and Monterey, and near the coast palmettoes and cocoanuts; Australian eucalyptus, tall with strangely-set foliage and tasseled flowers; handsome liquidambar with star-shaped leaves that turn to red and purple in the fall; the pleasant-fruited pecan (Hicoria); mulberries (Morus) whose soft fruit is so attractive to birds that the tree is sometimes planted to allure them from more valuable fruits, and luscious figs (Ficus). The Pride-of-China tree (Melia) is another favorite food-tree of birds who are said to occasionally intoxicate themselves with its rather poisonous translucent berries. Pepper trees (Schinus) and the madrona (Arbutus) laden with scarlet berries, are also frequented by birds. The crape myrtle (Lagerstræmia) with crinkled petals of rose and white, the blazing royal poinciana (Poinciana); the handsome golden-flowered Cassia fistula; the whole tribe of wattles (Acacia) including the fragrant-flowered cassie (A. farnesiana); the fern-leaved silk-oak (Grevillea) and the weird she-oak (Casuarina) are well-known exotics frequently planted. Among the natives are the blue-flowered California lilac (Ceanothus), the magnificent magnolias and the loblolly bay (Gordonia).
The South, again, can have a wonderful collection of flowering shrubs, both native and foreign, some of which are cultivated in the window gardens and greenhouses of the North. Such are the oleander (Nerium) bearing great sprays of pink or white or cream flowers; Chinese Hibiscus, or shoe-black plant, tossing its gay flowers with long projecting column out of every shrubbery; the pomegranate (Punica), its flowers of pure vermilion followed by heavy fruit that pulls down the slender branches; golden Allamandas, half-climbing in habit, azure phlox-like Plumbago; stiff waxen Ixoras of many hues, the scentless Camellias, and all those shrubs of different families called jessamine, scented and white and waxen of petals. One is the Cape jessamine better known at the North as Gardenia; another is the crape jessamine (Tabernæmontana) the rose-bay of India; still another is the Confederate jasmine (Trachylospermum) with delightful flowers like tiny children's windmills. Among native shrubs are the Stuartia with large white flowers; the lovely Matilija poppy (Romneya); Bauhinias, with orchid-like flowers, gorgeous Lantanas; the sea-side mahoe (Paritium), with effective yellow flowers like hollyhocks; Daturas with huge white nodding trumpets and many others.
The calico bush (Manzanita) thickly bedecked with fragrant white bells (Arctostaphylos) also noted for the rich color of bark and twigs; the extraordinary tree-yuccas (Yucca); Californian holly (Heteromeles), whose cardinal-berried sprays are used for Christmas decoration; that barberry (Berberis), with holly-like foliage, called most frequently Mahonia; the golden-flowered Fremontia; the tree-mallow (Lavatera); the tasseled Garrya; and the fragrant California laurel (Umbellularia) are often seen in Western and Pacific Coast plantations.
There is, however, no lack of flowering or fruiting shrubs for the more severe climates, and a certain amount of garden-color may be procured for even the dreary winter season, by planting broad-leaved evergreens, such as the stiff formal box (Buxus); hollies (Ilex); mountain laurel (Kalmia) and Rhododendron, the last two being even more desirous when in bloom. Dwarf conifers also, as the spreading Canadian yews (Taxus), junipers (Juniperus) and low pines (Pinus) form masses of grateful green in the foreground of shrubberies. Certain cornels (Cornus), which bear cymes of Eretty flowers in summer, followed by white or blue fruit, are remarkable for their brightly colored twigs in winter; likewise willows (Salix), brightening toward spring, and Kerria, are useful for their tinted bark.
All those shrubs which bear winter berries are also important for color; they include sumach (Rhus); burning-bush (Euonymus) and its allies; barberries (Berberis); wild roses (Rosa); and deciduous hollies, especially that known as black alder; wax-myrtles and bayberries (Myrica), most of which also afford a winter fare for hard-weather birds. Others that are tempting to the avian palate, but which mature earlier are the spice-bush (Benzoin); choke-cherries (Prunus); red- and black-fruited elderberries (Sambucus); oleaster (Eleagnus); service-berries (Amelanchier); buckthorn (Rhamnus); sea-buckthorn (Hippophæ); buffalo berries (Shepherdia) and the white fruited snowberry (Symphoricarpos).
Among the flowering shrubs one can have blossoms in early spring on fragrant mezereon and Daphne (Daphne); on the sweet-scented Asiatic bush honey-suckles (Lonicera); on the drooping golden bell (Forsythia), and the scentless yellow jasmine (Jasminum nudiflorum) . These are swiftly followed by pink and flaming azaleas; by the chocolate-colored, spicily-fragrant “Sweetshrub”; by Golden-flowered Kerria; by lilacs (Syringa) in all shades of purple and white; by flowering almonds (Prunus) and graceful snowy Deutzias; Kalmias and Rhododendrons come in June and July with a gorgeous company of Spiræas, some with hemispherical heads of white, some shooting up into spires of pink tiny blossoms. Huge snowballs (Viburnum) follow, the old-fashioned guelder-roses and the equally well-known Rose-of-Sharon (Hibiscus), tree-like covered with flowers like hollyhocks, pink or white. Single wild roses (Rosa) as the pink prairie-rose, the eglantine with lemon-scented foliage, and the robust Japanese roses are suitable for hedge-rows, in company with heavily scented mock-oranges (Philadelphus); pepper-bush (Clethra) and late white Azaleas; and with the scentless but floriferous raspberries (Rubus); garlanded pink Weigelas (Diervilla); the blue-spired Buddleia, delightful to butterflies; the smoke-like puffs of Rhus Cotinus and the heavy heads of Hydrangeas of ever-changing tints.
The seashore claims its own peculiar shrubby flora. Among those shrubs that may be planted along the dry strand are feathery Tamarix, each spray tipped with a wand of delicate rosy bloom; the native dark-colored aromatic bayberry (Myrica), dense clusters of high-water shrub, (Iva), fleshy-leaved like its neighbor, the Baccharis, which in autumn is smothered in white down of its fruits; and where the climate permits, wattles (Acacia) that are excellent sand-binders. Beach-plums wreathed with white bloom in early spring, hung with blue fruit in fall, and the creeping matted bearberry, thickly studded with scarlet berries, will thrive in sandy wastes.
Vines carefully trained over trellis or wall or tree are valuable for ornamental as well as for the more prosaic purpose of screens. Since their methods of ascension are different, these must be taken into consideration. Virginia creeper and its familiar relative, the Boston ivy (Ampelopsis) raise themselves by sucker-like discs at the end of tendrils, and are especially suited for creeping up walls, rocks and tree-trunks. European ivy (Hedera) and the American creepers (Tecoma) which ascend by thrusting out aerial rootlets, are equally adaptable for this use. Other common vines climb by tendrils or by weaving, twining or scrambling and are therefore useful for twisting about wires, or weaving into the meshes of a trellis. Wistarias are familiar examples of this sort, often becoming in age self-supporting, dropping their heavy purple and white racemes from tree-like trunk and branches. Bittersweet (Solanum), covered with purple star-flowers in summer and with yellow and scarlet berries in fall; honeysuckles (Lonicera) prodigal of scented yellow or pink or white blossoms or unscented red ones; Clematis, bearing either large formal flowers of white or purple, or small clusters of small white ones of the type known as traveler's joy, succeeded by gray fluffy seed-balls of feathery-tailed fruit; fragrant cinnamon vine (Dioscorea); matrimony vine (Lycium) throwing out long wands freighted with scarlet berries; Akebia quinata, delicate in foliage and gay in fruit; far-scrambling wild cucumber (Echinocystis); and humble gourds of all shapes with the hop (Humulus), laden with pale friut, form verdurous screens.
Our wild bittersweet, or wax-work (Celastrus scandens) gorgeous with scarlet and gold far into winter; the delicate mountain-fringe (Adlumia) with its fern-like foliage and pink, saccate blossoms and the ground-nut (Apios) wreathed with violet-scented balls of old-rose tinted blossoms, are perhaps best left to garland fence and hedgerow. Climbing roses, such as the Baltimore Belle, the ubiquitous ramblers and various hardy hybrids are useful for trellis and garden arches, one of the best being the native prairie-rose (Rosa setigera) and its varieties. The South, however, can grow a number of climbing roses like the deliciously fragrant yellow Marechal Niel, the Gloire de Dijon and the wonderful single white Cherokee rose which takes possession of hedges. They have also the fragrant yellow jessamine (Gelsemium sempervirens) and the exotic star-flowered, perfumed white jasmines (jasminum) as well as the tropical Solanums with large blue flowers.
Climbing also in those favored lands are the incomparably blue Clitoris ternatea, purple and brick-red Bougainvillæas, smothered by their papery triple bracts; the gayly-colored climbing lily (Gloriosa superba), shell-pink rosa-de-montana (Antigonon) flinging its branched coral-like sprays in wild profusion; Clerodendrons with scarlet corollas peeping out of white bag-like calyxes; Thunbergias, some small, white or yellow with purple eye, some huge of leaf, fringed with long racemes of gigantic velvety flowers of white or purple. They have, too, quaintly-flowered Aristolochiæ, grotesquely shaped, strikingly reticulated with pale veins on a purplish or brownish velvety ground.
Convolvuluses are rampant in tropical climes, and great moonflowers, and the satiny chalices of pink and white and blue are common there, as well as the charming cypress-vines (Ipomæa) with delicately cut foliage, which are grown at the North as annuals.
If the size of the place prohibits the use of many trees or even of shrubs, there are still a number of perennial plants that are large and conspicuous enough to be truly decorative. Pæonies form an important group of extremely hardy herbaceous plants, being found in many single and double varieties and as many hues, often rose-scented, moreover. Irises are a close second, having a bewildering number of species, types and colors, a constant succession of varieties being obtainable from early spring to midsummer. Lilies (Lilium), too, include many species of many colors, but always decorative and graceful, very often fragrant Daylilies (Hemerocallis; Funkia) are also very decorative and form huge clumps, the orange and yellow varieties liking moisture and full sunshine, while the white and blue kinds prefer shade; this preference is shared by fragrant lilies-of-the-valley (Convallaria) which carpet wide ground-space, and by evergreen, trailing periwinkles (Vinca) starred with purple blossoms in early spring. Some of the members of that large group, Campanula, both blue and white, also like shady places, and one species, the bluebells of Scotland is never so happy as when perched on rocky slopes or cliffs. It is one of the best plants for a simple rockery, sharing the damp stony location with dancing columbines (Aquilegias). Rosetted Saxifrages and Sedums, trailing Phloxes, sweetscented Daphne, and the scrambling rose (Rosa wichuriana) are all fit subjects for the sunnier aspects of a rockery, or for hot banks.
Aconites with cowl-like flowers of rich purple or yellow, Virginia bluebells (Mertensia); tall white Phloxes, and fragrant sweet rocket (Hesperia); scarlet and violet bee-balms (Monarda); and the stately foxgloves (Digitalis) are striking border plants for more or less shady places. In the full sun we may find the annual humble but glowing sunflower (Helianthus) splendid screening plants; azure larkspurs (Delphinium), ever a lure for humming birds; gray-green grass-pinks (Dianthus) profuse of fragrant bloom in June and evergreen throughout the winter, and the picturesque holyhocks (Althæa). Hardy old fashioned pompon Chrysanthemums bloom gorgeously far into fall undisturbed by frosts, the stiff papery flowers of immortelles, the satin discs of honesty (Lunaria), and the vermilion, inflated calyxes of the Chinese lantern plant (Physalis), lend their cheer to the late garden, followed by the stiff waxy blossoms ot the Christmas rose (Helleborus).
Southern climates permit of the culture of green-white Eucharis; Pancratiums and Crinums of varied hues; of viciously-armed Cacti and the stiff Aloes, Agaves and Yuccas, extremely decorative with their formal tufted growth and pyramidal bloom. There hothouse plants of the North, Heliotropes, Fuchsias, Begonias and Geraniums, become bushes, and the tea-rose blooms perpetually. They have also the gaudy dwarf Poinciana and the even more brilliant Poinsettias and Acalyphas (Arundo). Shrubby lantanas choke roadsides, and Bamboos and giant reeds form thickets.
Swampy lands and quiet pools, natural or artificial, filled with tepid water and with goldfish for the reduction of mosquitoes, can be turned into most decorative features, as bog- or aquatic-gardens. In the moist soil of the bog-gardens can be planted a variety of native plants such as the purple ironweed (Vernonia); the old-rose gigantic Joe-Pye-weed, and its smaller congener, the massive-headed, white boneset (Eupatorium); the vivid cardinal flower (Lobelia) and its blue relative; the pale turtle-head (Chelone) topheavy with its long continuing masses of oddly-inflated blossoms; yellow and magenta Lysimachias; goldenrods (Solidago); Asters and some of the more conspicuous orchids. The flaunting rose-mallow (Hibiscus), and marshmallow (Althæa) may also be suggested. The most splendid aquatic plants are in the genus Nelumbium, or lotus, our native species being pale yellow and the Oriental, pink or white, raised high in the air over huge umbrella-like leaves. Various waterlilies (Nymphæa) some hardy, and others tender, in the North, float on the surface of the pond, with the humble spatter-dock and the purple water-hyacinth (Eichornia) which is become such a pest in Southern water-ways, and gay water-poppies (Limnocharis).
Tall blue spikes of pickerel-weed (Pontederia) and the white fugitive flowers of the arrow-head (Sagittaria) and tufts of umbrella plant and andent papyrus (Cyperus) rise above the water. Consult Bailey, L. H., ‘Cyclopedia of American Horticulture’ (New York 1904); ‘How to Make a Flower Garden’ (New York 1903).