Encyclopædia Britannica, Ninth Edition/Rose

ROSE (Rosa). The rose has for all ages been the favourite flower, and as such it has a place in general literature that no other plant can rival. In most cases the rose of the poets and the rose of the botanist are one and the same in kind, but popular usage has attached the name rose to a variety of plants whose kinship to the true plant no botanist would for a moment admit. In this place we shall employ the word in its strict botanical significance, and in commenting on it treat it solely from the botanical point of view (see also Horticulture, vol. xii. p. 260). The rose gives its name to the order Rosaceæ, of which it may be considered the type. The genus consists of species varying in number, according to the diverse opinions of botanists of opposite schools, from thirty to one hundred and eighty, or even two hundred and fifty, exclusive of the many hundreds of mere garden varieties. While the lowest estimate is doubtless too low, the highest is enormously too large, but in any case the wide discrepancies above alluded to illustrate very forcibly the extreme variability of the plants, their adaptibility to various conditions, and consequently their wide dispersion over the globe, the facility with which they are cultivated, and the readiness with which new varieties are continually being produced in gardens by the art of the hybridizer or the careful selection of the raiser. The species are natives of all parts of the northern hemisphere, but are scantily represented in the tropics unless at considerable elevations.

They are erect or climbing shrubs, never herbs or trees, generally more or less copiously provided with thorns of various shapes and with glandular hairs, as in the sweet brier or in the moss rose of gardens. The thorns serve the purpose of enabling the shrub to sustain itself amid other vegetation, and perhaps in some sort serve as a protection against marauders. The viscid hairs which are specially frequent on the flower stalks or in the neighbourhood of the flower serve to arrest the progress of undesirable visitants, while the perfume emitted by the glands in question may co-operate with the fragrance and colour of the flower to attract those insects whose presence is desirable. The leaves are invariably alternate, provided with stipules, and unequally pinnate, the stipules themselves being in this case perhaps merely the lowest pair of “pinnæ” or leaflets less perfectly developed than the others. The flowers are solitary or in loose cymes (cluster-roses) produced on the ends of the shoots. The flower-stalk expands into a vase- or urn-shaped dilatation, called the receptacle or receptacular tube, which ultimately becomes fleshy and encloses in its cavity the numerous carpels or fruits. From the edge of the urn or “hip” proceed five sepals, often more or less compounded like the leaves and overlapping in the bud. Within the sepals are five petals, generally

broad or roundish in outline, with a very short stalk or none at all, and of all hues except blue. The very numerous stamens originate from about the same spot as the sepals and petals; each has a slender filament and a small two-celled anther. The inner portion of the receptacular tube whence the stamens spring is thick and fleshy, and is occasionally spoken of as the “disk”; but, as in this case it does not represent any separate organ, it is better to avoid the use of the term. The carpels are very numerous, ultimately hard in texture, covered with hairs, and each provided with a long style and button-like stigma. The carpels are concealed within the receptacular tube and only the stigmas as a rule protrude from its mouth. Each carpel contains one ovule without perisperm. The so-called fruit is merely the receptacular tube, which, as previously mentioned, becomes fleshy and brightly coloured as an attraction to birds, which devour the hips and thus secure the dispersion of the seed. The stamens are in whorls, and, according to Payer, they originate in pairs one on each side of the base of each petal (parapetalous), so that there are ten in each row; a second row of ten alternates with the first, a third with the second, and so on. By repeated radial and tangential branching a vast number of stamens are ultimately produced, and when these stamens assume a petaloid aspect we have as a consequence the double flowers which are so much admired. The carpels are much less subject to this petaloid change, and, as it generally happens in the most double of roses that some few at least of the anthers are formed with pollen, the production of seed and the possibility of cross-breeding become intelligible. Under natural circumstances rose flowers do not secrete honey, the attraction for insects being provided, according to Müller, by the colour and perfume and the abundance of pollen for food. The stigmas and anthers come to maturity at the same time, and thus, while cross-fertilization by insect agency is doubtless most common, close fertilization is not prevented.

In The Student's Flora Sir Joseph Hooker recognizes seven species of Rosa as British. Among them may be mentioned R. spinosissima, the Scotch Rose, much less variable than the others, R. rubiginosa, the Sweet Brier, represented by several varieties, R. canina, the Dog Rose, of which no fewer than twenty-nine varieties are described, and R. arvensis. Cultivated roses are frequently “budded” or worked upon the stems of the brier or R. canina, or upon young seedling plants of the same species. Other species also are used for stocks (see Horticulture). Roses have been grown for so many centuries and have been crossed and recrossed so often that it is difficult to refer the cultivated forms to their wild prototypes. The older roses doubtless originated from R. gallica, a native of central and southern Europe. R. centifolia (the Cabbage Rose), a native of the Caucasus, contributed its share. A cross between the two species named may have been the source whence originated the Bourbon Roses. The yellow-flowered Austrian and Persian Brier originated from R. eglanteria, a native of Austria. The Monthly or China Roses sprang from the Chinese R. indica, and these crossed with others of the R. centifolia or gallica type are the source of the hybrid perpetuals so commonly grown nowadays, because, in addition to their other attractions, their blooming season is relatively prolonged, and, moreover, is repeated in the autumn. Tea Roses and Noisettes, it is to be presumed, also acknowledge Rosa indica as one of their progenitors. The Banksian Rose is a Chinese climbing species, with small white or fawn-coloured flowers of great beauty; the Macartney Rose (R. bracteata) is also of Chinese origin. Its nearly evergreen deep green leaves and large white flowers are very striking. The Japanese R. rugosa is also a remarkable species, notable for its bold rugose foliage, its large white or pink flowers, and its conspicuous globular fruit. R. damascena is cultivated in some parts of Roumelia for the purpose of making attar of roses (see Oils and Perfumery). According to Hanbury, the flowers are gathered before sunrise and distilled the same day. The distilled liquid is allowed to remain for a day or two, by which time most of the oil will have risen to the surface, from which it is skimmed off. The percentage yielded is very small, not more than 0.04.

In India R. damascena is grown largely near Ghazipur for the purpose of procuring attar of roses and rose water. The roses are distilled with double their weight of water. The attar is skimmed off in the Turkish method. Colonel Drury mentions that it takes 200,000 roses to yield the weight of a rupee in attar. This quantity sells on the spot for 100 rupees. Rose water is chiefly produced in Europe from the Provence or cabbage rose, R. centifolia, grown for the purpose at Mitcham and much more abundantly in the south of France. Conserve of roses and infusion of roses, two medicinal preparations retained for their agreeable qualities rather than for any special virtue, are prepared from the petals of Rosa gallica, one variety of which was formerly grown for the purpose near the town of Provins. Conserve of dog rose is made from the ripe hips of the dog rose, Rosa canina. Its only use is in the manufacture of pills.

The name Rose of Jericho is popularly applied to a small Cruciferous weed, Anastatica hierochuntina, a native of the desert regions of Egypt, Arabia, Palestine, and Persia. In the dry season the dead branches are strongly incurved, and thus serve to protect the still living seed in the pods. In the wet season the branches absorb the moisture to a large extent, unfold, resume the direction they had in life, and facilitate the dispersion of the seed under circumstances favourable to germination. The plant is frequently carried off as a curiosity, inasmuch as immersion in a basin of water enables it to resume the original form and to create the impression that the plant “comes to life again,” but the process is purely a physical one.