Rose Annual 1919 pp. 14-20
DR. W. VAN FLEET
Department of Agriculture, Washington, D. C.
EDITOR'S NOTE.—It was a visit to Dr. Van Fleet's interesting perfume-garden at Arlington, under his guidance, that suggested the desirability of an account of fragrant roses. Dr. Van Fleet has kindly provided information and suggestion, and the article which follows is the last word on the subject. Who noted before that there was no odor of musk in the Musk rose, and none of cinnamon in the Cinnamon rose?
AGREEABLE fragrance is one of the most valued attributes of the perfect rose, though many indispensable species and varieties do not possess it in marked degree, and not a few are either odorless or even distasteful to the sense of smell. The name Rosa foetida was given to the wild yellow rose of Persia by Herrmann in 1762, under the impression that the blooms had an unpleasant odor, and this offensive designation has been revived by the later botanists under the rule of priority, but it is safe to say that rose-lovers will continue to use R. lutea when referring to the botanical status of the yellow Brier group.
The flowers of the Persian and Harison's Yellow roses are practically scentless, while the foliage gives out, under moist conditions, a perceptible Sweetbrier fragrance. R. xanthina, one of the yellow roses of western China, and R. Ecae, of Abyssinia, have, in some of their forms, foliage that emits during damp weather a keen and far from agreeable formic-acid smell that could have suggested the idea of fetor in a rose plant to an unappreciative systematist. The blooms of R. xanthina, R. Ecae, R. Hugonis, and R. persica, or the berberis-leaved rose—all yellow-flowered, oriental species—are either scentless or possess only a mere suggestion of the unwelcome hawthorn odor apparent in many forms of R. multiflora and R. moschata.
Passing from the unedifying consideration of roses with unpleasing odors to the really fragrant kinds, one may broadly state that the wild roses inhabiting the coastal regions of the Mediterranean Sea and the eastern shores of the Pacific and Atlantic oceans in the north temperate zone possess agreeable fragrance in the highest degree, while those native to the interior uplands of the respective continents are, to a great extent, devoid of this pleasing attribute. Thus, R. rugosa, of Japan and Siberia, R. gallica and R. centifolia, of the Mediterranean countries, R. virginiana and R. humilis, of our Atlantic coastal states, typify rose-perfume in its most pleasing form—the true oil or attar-of-rose fragrance. We may well call this the Centifolia odor, as R. centifolia and related species form the foundation of the attar-of-rose industry, In the foothills of India grows the gigantic R. odorata, which, in its dwarf form, typifies the tea-scented rose varieties of our gardens.
The wild roses of North Europe mostly have faint fragrance or are scentless, and the same may be said of our Middle West and Pacific Coast species, though there are a few exceptions in the extreme Northwest. R. setigera, the scentless Prairie rose, is a characteristic example of the lack of fragrance of the rose species of our interior country.
Passing to the various forms of rose-fragrance, the violet-like odor of R. Banksiae may be mentioned. It is faint, but it will be recognized when thousands of blooms are expanded at the same time, as in the enormous plants so common in California. The cinnamon odor ascribed to R. cinnamomea and kindred species has never materialized in the blooms or foliage of any of the plants I am familiar with. The cinnamon idea is more easily associated with the color of the twigs than with any odor that arises from flower or foliage.
Mention has already been made of the none-too-agreeable crataegus-like or hawthorn odors that prevail in many wild roses of the Multiflora and Musk rose group. All species do not have it, and it usually is found in diminished intensity in the cultivated forms. I have yet to find a Musk rose, wild or cultivated, that emits anything resembling the real odor of musk.
True rose-fragrance arises from the presence of rose-oil or attar, a volatile oil elaborated in the petals of the blooms just before opening. It appears most abundantly in the cells near the base of the petals, yet is present in such small quantities that it usually requires a ton and a half of fresh-plucked rose petals to produce a pound of oil.
Rose-attar, at ordinary temperatures, more resembles a brownish butter than an oil, and is distinct from any other product of nature. Oils somewhat resembling it in odor are distilled from a species of pelargonium and from a South American wood. A base imitation, only fit for use in cheap soaps and unguents, is manufactured synthetically from coal-tar products, but true rose-attar can always be distinguished by the expert.
The agreeable tea-like fragrance of the tender everblooming roses of the R. odorata group is of a different character. It cannot be extracted by distillation, and is only feebly preserved by the grease or enfleurage process of recovering flower perfumes, but, when united by hybridization with the attar-scented roses, there results the still more exquisite perfumes found in the various Hybrid Tea varieties.
There is one remaining entrancing rose odor—the despair of perfumery chemists!—that of Sweetbrier foliage after a rain. It cannot be recovered by any known process, and lives and dies with the occasion during which it is perceived. That would be a happy day in which science had been able to fix and preserve this delightful odor! The unpleasant ant-hill or formic-acid smell of the leaves of R. xanthina and R. Ecae in the early morning, and after rains, has already been mentioned, and is only to be gotten rid of by choice of the proper varieties of these species, otherwise so desirable for their earliness and for the rare yellow color of the neat little blooms. R. Hugonis, also early and yellow-flowered, in my experience does not possess this disagreeable feature, and is in many ways better than either.
Attar of roses is secured from the fresh petals of fragrant roses by the ordinary processes of distillation and condensation used to recover all essential or volatile oils produced in nature, and no very elaborate or costly apparatus is needed for the purpose. It exists in such small quantity, however, even in the best perfume varieties—thirty-five to forty large blooms being required for a single drop—that it remains in solution in the water of condensation that comes over from the still, and must be washed out with ether or redistilled several times before it may be skimmed off, as with more abundant oils. These first waters, however, are most deliciously scented, and, in this country at least, would be more valuable as true commercial rose-waters than the attar itself when extracted from them.
Commercial rose-attar has hitherto been produced in southern France, where it has long been an important industry, and in Bulgaria, Turkey, and Germany in about the order named. Every effort should be made to encourage the industry in France, but the memory of the other countries will long remain a stench in the nostrils of civilization.
The rose varieties used for the purpose in all the countries concerned in perfume production are about the same, mostly natural hybrids of R. centifolia and R. gallica, the former predominating where quality, and the latter where quantity, of product is most highly appreciated. There is an approach to nature in R. centifolia minor and R. gallica officinalis, but neither, in all probability, represents the true wild type, and they are little used in practical operations. R. gallica in its simpler forms is about as sweet as R. centifolia and is a taller and more vigorous grower, but with less abundant petals. In its divergent types, such as R. alba and R. damascena, the former much grown in Bulgaria, the fragrance is less agreeable than in R. centifolia.
The practical perfume varieties all increase by suckers from the large surface-roots, and the usual procedure is to tear apart the clumps after eight or more years of cropping and reset the rooted canes and suckers in new soil. All have but one short season of intensive bloom in spring, giving rise to a great need for labor during picking-hours, which are limited to early morning. This is the most expensive operation connected with rose-attar production, wherefore varieties of equal merit, blooming over a longer period, have long been desired.
The late Monsieur Jules Gravereaux, the famous rose collector of L'Hay in France, sought with marked success to develop continuous-blooming perfume varieties by hybridizing R. rugosa, one of the sweetest of wild roses, with the best varieties grown for practical attar distillation. Rose Parfum de l'Hay is the best known of his productions, and has been tried in some quantity in the Arlington perfume experiments of the United States Bureau of Plant Industry. Blooms from 800 plants were collected and distilled for several seasons, in comparison with those of most other perfume roses, the result showing that it is at least equal, under our conditions, in yield and quality to the best of the kind in general use. The amount of attar obtained worked out to more than the general average rate of one pound to 8,000 pounds of fresh petals, and the quality is undeniably high. Only one other variety, Mrs. Curzon, evidently a Centifolia-Gallica hybrid, with the cabbage rose type predominating, greatly exceeded this average, giving almost double the relative yield, but the blooms were rather scantily produced during the usual short spring season. Rose Parfum de l'Hay blooms plentifully in June and at intervals throughout the summer and autumn, the late flowers being especially abundant in August, the seasonal production appearing to be considerably greater than that of the excessive spring bloomers. Thus the labor of collecting and distilling the petals extends over a far longer interval and should be accomplished by a smaller force of workers. In common with many Rugosa hybrids, it can only be obtained as plants budded or grafted on the usual rose stocks, making it more expensive and less useful than sucker-grown varieties that reproduce themselves from root-buds.
The writer has effected many hybridizations of R. rugosa and some of our most fragrant native species with the Old-World perfume roses during the past twenty years, but no Varieties of practical merit are yet in sight. If we wish to stock up on commercial perfume producers of this character, we will have to go to the south of France for the start.
The Arlington experiments seem to show that the cultivation of perfume roses in this country and the working up of their products presents no practical difficulty except that of differences in labor costs. There are, doubtless, in the Appalachian region, thousands of acres of well-watered upland soils of the somewhat heavy character favored by deep-rooting roses, as well suited for perfume culture as any in France or Bulgaria, and with requisite persistence the industry could be established here if the promoters were not too keen for quick profits. As with commercial tea-growing, provision would have to be made to gather and care for the special labor needed for picking the blooms when ready.
European chemists, with characteristic cynicism, have devoted much energy to the problem of adulterating rose-attar so that it will pass muster with the importing fraternity, and it is safe to say that very few ounces ever reach this country in its pure state. The production of genuine rose perfume preparations, wholly originating in America, might establish a standard that Europe and the Orient would find it difficult to ignore.
The fragrance of our garden and exhibition roses, without doubt, comes in the first instance from the hybridization of R. chinensis, a species naturally of faint fragrance, with R. gallica, of Europe, giving rise to the deliciously scented Hybrid Perpetuals of old gardens, and, recently, by the crossing of these with R. odorata, to production of the immensely popular Hybrid Teas, some of which are intensely fragrant, while others entirely lack this most desirable quality. Tea roses themselves have their own characteristic fragrance, as is typified by the name, and this, in many instances, blends well with heavier Centifolia odor, rising occasionally to the highest pitch of pungent sweetness. The blend of tea-scent with muskiness in some of the dwarf Polyanthas is agreeable, but the Centifolia fragrance is rarely brought out in hybrids between R. multiflora and varieties or species carrying Centifolia odors.
Rose aromas are not congenial to all persons, and occasionally an individual is found to whom they are annoying, and even hurtful, in the way of causing catarrhal symptoms; but to the overwhelming majority of gardeners, fragrance is a prime requisite for the thorough enjoyment of a rose bloom.
We will all continue to grow Frau Karl Druschki until we can get a hardy, white outdoor rose at least as good that includes the fragrance so noticeably lacking in this indispensable variety. There are many lists of fragrant garden roses that vary much with the taste and experience of the compiler. The following species and varieties have proved themselves satisfactory to the writer, but their number could greatly be increased.
Rosa rugosa: Common type R. rugosa, R. rugosa alba and magnifica, Souvenir de Pierre Leperdrieux, Blanc Double de Coubert, Calocarpa, Parfum de l'Hay, Conrad F. Meyer, and New Century.
Rosa virginica, or lucida, type and variety alba; R. humilis.
R. nitida: R. centifolia in the old Cabbage roses and the Moss roses, Gracilis and Crested Moss; R. gallica in Damask and Provence varieties: the typical form of R. gallica officinalis.
Rosa bella is the most fragrant of the new Chinese species that has come to my hand, and is well worth growing in any garden in which room can be spared for wild roses.
Hybrid Perpetuals. Most of the older Hybrid Perpetuals are gratefully fragrant. Among the best are Alfred Colomb, Captain Hayward, Fisher Holmes, Gen. Jacqueminot, Gloire de Margottin, Jean Liabaud, Hugh Dickson, Magna Charta, Marshall P. Wilder, Mrs. Charles Wood, Paul Neyron, Prince Camille de Rohan, and Victor Hugo. There are many others.
Hybrid Teas. The list of highly fragrant Hybrid Teas is a long one, and there are also many that are quite devoid of odor. In a selection for a bed in the perfume-garden, American Beauty (which, to be honest, we should call Mme. Ferdinand Jamain) would take high rank, unless it is preferred to regard it as a Hybrid Perpetual. A few varieties of special excellence are Augustine Guinoisseau, Chateau de Clos Vougeot, George Dickson, Gen. MacArthur, Gruss an Teplitz, La France, Lieutenant Chaure, Magnafrano, and Princess Bonnie.
Tea Roses. Teas are nearly all desirable for the delicate and sprightly tea-like odor exhaled by the blooms. Few are lacking in this respect. Among the best are Bon Silene, Devoniensis, Safrano, and Isabella Sprunt. The yellow Teas are fragrant to a noticeable extent, and this characteristic extends to the hybrid climbing forms, such as Lamarque and Marechal Niel, usually classed as Noisettes. Climbing Niphetos and Climbing Perle des Jardins are most fragrant of the pure Tea climbers.
Fragrant Hardy Climbing Roses. In this class there appears nothing better than Ards Rambler, Birdie Blye, Reine Marie Henriette and Zephirine Drouhin, although Mme. d'Arblay and R. Wichuraiana have delicate odors not to be overlooked.
Roses with Scented Foliage. Rosa rubiginosa, the Sweetbrier, stands first in the list; R. agrestis has a similar quality in less degree, followed by Harison's Yellow, Persian Yellow, and a few other derivatives of R. lutea. The Sweetbrier hybrids, with the exception of Lord and Lady Penzance, do not possess fragrant foliage in noticeable degree, though the blooms of several varieties are pleasantly perfumed.