Hardy Ornamental Flowering Trees and Shrubs Part 20

The flowering Currants are of unusually free growth, and are not at all particular about soil, often thriving well in that of a very poor description. They are increased readily from cuttings and by layers.

ROBINIA.

ROBINIA DUBIA (_syns R. echiuata_ and _R. ambigua_).--A very pretty garden hybrid form, said to have for its parentage R. Pseud-Acacia and R. viscosa. It is of quite tree-like growth and habit, with unusually short spines, and Pea-green foliage. The flowers are produced pretty freely, and are of a pale rose colour, and well set off by the light-green leaves, over which they hang in neat and compact spikes.

R. HISPIDA.--Rose Acacia. North America, 1743. Amongst large-growing shrubs this is certainly one of the most distinct and handsome, and at the same time one of the hardiest and readiest of culture. Under favourable conditions it grows about 16 feet high, with large oval or oblong leaflets, and having the young branches densely clothed with bristles. The flowers, which are individually larger than those of the False Acacia, are of a beautiful rosy-pink, and produced in June and July. It is a very ornamental, small growing species, and one that is peculiarly suitable for planting where s.p.a.ce is limited. R. hispida macrophylla (Large-leaved Rose Acacia) is rendered distinct by its generally more robust growth, and by its larger foliage and flowers. The species, however, varies a good deal in respect of the size of leaves and flowers.

R. PSEUD-ACACIA.--Common Locust, b.a.s.t.a.r.d Acacia, or False Acacia. North America, 1640. A n.o.ble-growing and handsome tree, with smooth shoots, and stipules that become transformed into sharp, stiff spines. The flowers are in long racemes, pure-white or slightly tinged with pink, and with a faint pleasing odour. This species has been sub-divided into a great number of varieties, some of which are very distinct, but the majority are not sufficiently so to warrant special attention. The following include the best and most popular kinds:--R. Pseud-Acacia Decaisneana, a distinct form bearing light pinky flowers; R.

Pseud-Acacia Bessoniana, with thornless branches and a dense head of refreshing Pea-green foliage; R. Pseud-Acacia angustifolia, with narrow leaves; R. Pseud-Acacia aurea, a conspicuous but not very constant golden leaved form; R. Pseud-Acacia inermis, of which there are weeping, upright, and broad-leaved forms, has narrow leaves that are glaucous beneath, and the characteristic spines of the species are wanting or rarely well developed. R. Pseud-Acacia monophylla is very distinct, the leaves being entire instead of pinnate; while R. Pseud-Acacia crispa has curiously-curled foliage. Then there is the peculiar R. Pseud-Acacia tortuosa, of ungainly habit; R. Pseud-Acacia umbraculifera, with a spreading head; R. Pseud-Acacia sophoraefolia, the leaves of which resemble those of Sophora j.a.ponica; and R. Pseud-Acacia amorphaefolia, with very large foliage when compared with the parent tree. The above may be taken as the most distinct and desirable forms of the False Acacia, but there are many others, such as R. Pseud-Acacia colutoides, R. Pseud-Acacia semperflorens, and R. Pseud-Acacia Rhederi, all more or less distinct from the typical tree.

R. VISCOSA (_syn R. glutinosa_).--Clammy Locust. North America, 1797.

This is a small-growing tree, and readily distinguished by the clammy bark of the younger shoots. Flowers in short racemes, and of a beautiful rose-pink, but varying a good deal in depth of tint. It is a valuable species for ornamental planting, and flowers well even in a young state.

Few soils would seem to come amiss to the Acacias, but observations made in many parts of the country conclusively prove that the finest specimens are growing on light, rich loam overlying a bed of gravel.

They are propagated from seed, by layers, or by grafting.

ROSA.

ROSA ALBA.--This is a supposed garden hybrid between R. canina and R.

gallica (1597). It has very glaucous foliage, and large flowers, which vary according to the variety from pure white to rose.

R. REPENS (_syn R. arvensis_).--Field Rose. Europe (Britain). This species bears white flowers that are produced in threes or fours, rarely solitary. The whole plant is usually of weak and straggling growth, with shining leaves.

R. BRACTEATA (Macartney Rose), R. PAl.u.s.tRIS (Marsh Rose), and R.

MICROPHYLLA (small-leaved Rose), belong to that section supplied with floral leaves or bracts, and s.h.a.ggy fruit. They are of compact growth, with neat, shining leaves, the flowers of the first-mentioned being rose or carmine, and those of the other two pure white.

R. CANINA.--Dog Rose. Our native Roses have now been reduced to five species, of which the present is one of the number. It is a straggling shrub, 6 feet or 8 feet high, and armed with curved spines. Flowers sweet-scented, pink or white, and solitary, or in twos or threes at the branch tips.

R. CENTIFOLIA.--Hundred-leaved, or Cabbage Rose. Orient, 1596. A beautiful, sweetly-scented species, growing to 6 feet in height, and having leaves that are composed of from three to five broadly ovate, toothed leaflets. The flowers are solitary, or two or three together, drooping, and of a rosy hue, but differing in tint to a considerable extent. This species has varied very much, princ.i.p.ally through the influences of culture and crossing, the three princ.i.p.al and marked variations being size, colour, and clothing of the calyx tube. There are the common Provence Roses, the miniature Provence or Pompon Roses, and the Moss Rose--all of which are merely races of R. centifolia.

R. DAMASCENA.--Damask Rose. Orient, 1573. A bushy shrub varying from 2 feet to 8 feet in height according to cultural treatment and age. The flowers are white or red, large, borne in corymbose cl.u.s.ters, and produced in great profusion during June and July. The varieties that have arisen under cultivation by seminal variation, hybridisation, or otherwise are exceedingly numerous. Those now grown are mostly double, and a large proportion of them are light in colour. They include the quatre saisons and the true York and Lancaster. The flowers are highly fragrant, and, like those of R. centifolia and other species, are used indiscriminately for the purpose of making rose water. The species is distinguished from R. centifolia by its larger p.r.i.c.kles, elongated fruit, and long, reflexed sepals.

R. FEROX.--North Asia. This species bears flowers in cl.u.s.ters of two and three together, terminating the branches. The petals are white with a yellow base. The branches are erect, and thickly crowded with p.r.i.c.kles of unequal size.

R. GALLICA.--The French, or Gallic Rose. Europe and Western Asia. This Rose forms a bushy shrub 2 feet to 3 feet high, and has been so long grown in British gardens that the date of its introduction has been lost in obscurity. It is doubtless the red Rose of ancient writers, but at present the flowers may be red, crimson, or white, and there are varieties of all intermediate shades. Several variegated or striped Roses belong here, including Gloria Mundi, a popular favourite often but erroneously grown under the name of York and Lancaster. They all flower in June and July, and, together with other kinds that flower about the same time, are generally known as summer or old-fashioned garden Roses.

R. HEMISPHAERICA (_syn R. sulphurea_).--Orient, 1629. A bushy plant growing from 4 feet to 6 feet high, and bearing large double yellow flowers.

R. INDICA.--Common China, or Monthly Rose. Introduced from China, near Canton, in 1789, but the native country is not known with certainty. The flowers of the plant when first introduced were red and generally semi-double, but the varieties now vary through all shades of blush, rose, and crimson, and the plant varies exceedingly in height, in its different forms 1 foot to 20 feet in height. The Monthly Roses form bushes generally about 2 feet high or a little over. The Noisette and Tea Roses, with several other more or less distinct types, belong here, but as most of them are well known and otherwise well cared for, it is unnecessary to dwell upon them in detail beyond the two varieties here given, and which should not be overlooked.

R. INDICA MINIMA (_syn R. semperflorens minima, R. Lawrenceana_, and _R.

minima_).--Fairy, or Miniature Rose. China, 1810. A beautiful little Rose that rarely exceeds a height of 4 inches or 5 inches. The flowers are about the size of a half-crown, and somewhat after the York and Lancaster as regards colouring, though not, perhaps, so distinctly marked, and are produced in abundance. For the rock garden it is one of the most desirable, and being perfectly hardy still further adds to its value.

R. INDICA SEMPERFLORENS (_syns R. bengalensis_ and _R.

diversifolia_).--The Ever-flowering China Rose. China, 1789. A somewhat spreading bush, with slender branches, armed with curved p.r.i.c.kles.

Leaves composed of three or five leaflets, and tinted with purple.

Flowers almost scentless, solitary, semi-double, and of a bright and showy crimson.

R. LUTEA (_syn R. Eglanteria_).--The Austrian Brier, or Yellow Eglantine. South Europe, 1596. This belongs to the Sweet Brier section, and is a bush of from 3 feet to 6 feet high, with shining dark-green leaves, and large, cup-shaped flowers that are yellow or sometimes tinged with reddish-brown within. The Scarlet Austrian Brier (R. lutea punicea) is a handsome variety, with the upper surface of the petals scarlet and the under surface yellow.

R. RUBIGINOSA (_syn R. Eglanteria_).--Eglantine, or Sweet Brier. This species has pink flowers and clammy leaves, which are glandular on the under surface, and give out a fragrant smell by which it may be recognised.

R. RUGOSA (_syn R. ferox of Bot. Reg._), a j.a.panese species, and its variety R. rugosa alba, are beautiful shrubs that have proved themselves perfectly hardy and well suited for extensive culture in this country.

They are of stiff, shrubby habit, about 4 feet high, and with branches thickly clothed with spines becoming brown with age. Leaflets oval in shape, deep green, with the upper surface rough to the touch, the under sides densely tomentose. Flowers single, fully 3 inches in diameter, the petals of good substance, and white or rose-coloured. The fruit is large, larger than that of perhaps any other rose, and of a bright red when fully ripe. In so far as beauty of fruit is concerned, this Rose has certainly no rival, and whether for the rockwork or open border it must be cla.s.sed amongst the most useful and beautiful of hardy shrubs.

R. rugosa is a capital hedge plant, and being a true species it is readily propagated from seed. R. rugosa Kamtschatika is a deep-red flowered form with deciduous spines.

R. SEMPERVIRENS.--Evergreen Rose. South Europe and India, 1529. A climbing species, with long, slender branches, armed with hooked p.r.i.c.kles. Leaves evergreen, shining, and composed of from five to seven leaflets. The cl.u.s.tered flowers are white and sweet-scented.

R. SPINOSISSIMA (_syn R. pimpinellifolia_).--Burnet, or Scotch Rose. A small bush about 2 feet high, of neat growth, with small leaves, and pink or white flowers that are solitary at the branch ends.

R. VILLOSA.--Downy Rose. Europe (Britain). This species is of erect bushy growth, with the leaflets softly downy on both sides. Flowers white or pale pink, succeeded by globular fruits, that are more or less covered with fine hair or p.r.i.c.kles.

ROSMARINUS.

ROSMARINUS OFFICINALIS.--Common Rosemary. Mediterranean region, 1848. A familiar garden shrub, of dense growth, with dusky-gray green linear leaves, and pale blue or white flowers. There is a golden and a silver leaved variety, named respectively R. officinalis foliis-aureis, and R.

officinalis foliis-argenteis; as also one distinguished by having broader foliage than the species, and named R. officinalis latifolius.

RUBUS.

RUBUS ARCTICUS.--Arctic Regions of both hemispheres. An interesting species about 6 inches high, with trifoliolate leaves, and deep-red flowers. For Alpine gardening it is a valuable species of dwarf growth.

R. AUSTRALIS, from New Zealand, is a very p.r.i.c.kly species, with the leaves reduced to their stalks and the midribs of three leaflets. Not being very hardy it is usually seen as a wall plant.

R. BIFLORUS.--Himalayas, 1818. A tall-growing species with whitish, spiny stems, and simple three-lobed leaves that are tomentose on the under sides. The flowers are thickly produced, pure white, and render the plant highly attractive, and of great beauty.

R. DELICIOSUS.--This Rocky Mountain Bramble (1870) is a very worthy species, with three or five-lobed (not pinnate) leaves, and large, pure white flowers that are each about 2 inches in diameter, and produced in profusion from the leaf-axils. For ornamental planting this may be placed in the first rank of the family to which it belongs.

R. FRUTICOSUS.--Common Bramble, or Blackberry. Of this well-known native species there are several worthy varieties, of which the double-flowered are especially worth notice, blooming as they do in the latter part of summer. R. fruticosus flore albo-pleno (Double white-flowered Bramble), and R. fruticosus flore roseo-pleno (Double red-flowered Bramble) are very pretty and showy varieties, and well worth including in any collection. There is a pretty variegated-leaved form of the common Bramble, known as R. fruticosus variegatus.

R. LACINIATUS, Cut-leaved Bramble, might also be included on account of its profusion of white flowers, and neatly divided foliage.

R. NUTKa.n.u.s.--North America, 1826. This has white flowers, but otherwise it resembles R. odoratus.

R. ODORATUS.--Purple flowering Raspberry. North America, 1700. The sweet-scented Virginian Raspberry forms a rather dense, upright growing bush, fully 4 feet high, with large broadly five-lobed and toothed leaves, that are more or less viscid, sweet-scented, and deciduous. The leaves are placed on long, hairy, viscid foot-stalks. Flowers in terminal corymbs, large and nearly circular, purplish-red in colour, and composed of five broad, round petals. The fruit, which is rarely produced in this country, is velvety and amber-coloured. It is a very ornamental species, the ample Maple-like leaves and large flowers rendering it particularly attractive in summer. The leaves, and not the flowers as is generally supposed, are sweetly scented.

R. ROSAEFOLIUS.--Rose-leaved Raspberry. Himalayas, 1811. Another half-hardy species, and only suited for planting against sunny walls.

Leaves pinnate, finer than those of the Raspberry. R. r. coronarius, with semi-double white flowers, is better than the type.

R. SPECTABILIS.--The Salmon Berry. North America, 1827. Grows about 6 feet high, with ternate or tri-lobate leaves that are very thickly produced. Flowers usually bright red or purplish-coloured, and placed on long pendulous footstalks. It is of very dense growth, occasioned by the number of suckers sent up from the roots.

There are also some of the so-called American Brambles well worthy of attention, two of the best being Kittatiny and Lawton's:

The brambles are particularly valuable shrubs, as owing to their dense growth they may be used for a variety of purposes, but especially for covering unsightly objects or banks. They are all wonderfully floriferous, and succeed admirably even in very poor and stony soils.

Increase is readily obtained either from root suckers or by layering.