Popular Science Monthly/Volume 45/September 1894/Barberries: A Study of Uses and Origins I
BARBERRIES: A STUDY OF USES AND ORIGINS. |
By FREDERICK Le ROY SARGENT.
THE common barberry (Berberis vulgaris), being so abundant over the greater part of Europe, native to the soil, and at the same time both useful and beautiful, has naturally come to hold an important place in popular esteem. As a consequence it has received, in the course of centuries, a considerable variety of names in the different European languages, and some of these names, as might be expected, have undergone rather curious transformations.
Our own name barberry is in England more commonly written berberry. The variants barbary, barbery, and berbery were used side by side in early modern English, as were barbere in still earlier English and berbere in the French of that time. There can be no doubt that these are descended from the mediæval Latin forms barberis and berberis, but further back than this the pedigree is uncertain.
In the change of the terminal from beris to berry we have, doubtless, an example of one of those transformations which are so apt to take place whenever the foreign name of a common object becomes incorporated into the vernacular, and the sound of the name suggests a common word in any way descriptive of the object. Just as the écrevisse (crevice-dweller) of the French became the "crayfish" of the English, from its aquatic habits. and the asparagus of the botanist is the "sparrergrass" or "sparrowgrass" of the marketman, so we may conclude that the character of the barberry's fruit decided the change of name referred to.
The first syllable of the English name is, doubtless, as unmeaning as the corresponding part of "crayfish" or its rival form "crawfish." Perhaps in both these cases the lack of any significance
Fig. 1.—Berberis vulgaris. Part of a long shoot, showing four spines and as many short branches bearing leaf rosettes.
in the first part of the words may have favored the continuance of two forms side by side.
Various conjectures have been offered as to the origin of the mediæval Latin barberis and berberis. Most commonly the Latin name is said to be derived from the Arabic barbārīs or berbérys;[1] but, according to Murray and the Century Dictionary, the Arabic form and the Persian barbari are both derivatives of the Latin. Wittstein[2] suggests a derivation from the Greek berberi, a mussel, from the mussel-like form of the leaves. The conjecture which assumes the plant to have been imported into Europe from Barbary, in Africa, does not harmonize well with what is known of the plant's distribution.
To return, then, to the Latin form, however it may have originated, we find it giving rise to the English berberry in a manner suggestive of adaptation to a new linguistic environment. By a somewhat similar process have probably arisen from the same original the form pepperidge, pipperage, piperidge, and piprage, by which the plant is popularly known in parts of England and Ireland. The ease with which the closely similar sounds b and p can pass one into the other, taken in connection with the obvious resemblance of the barbery fruit to small red peppers, doubtless gave direction here to the obscure forces which bring about the corruption of words.
The same Latin root makes its appearance in several names used in Germany. Thus, among those given by Adelung (1774) are Berbeisze, Berbis, Berwitze. The name most commonly met with in modern books is Berberitze, which, in view of the circumstance that ritzen means to scratch (apropos of the spines), surely looks like another case of assimilation, analogous to what we found in English. That the Germans are fond of embodying in their names of this plant some reference to its more or less obvious qualities or uses is sufficiently proved by the following list gathered from various lexicons: Sauerdorn (sour thorn), Essigdorn (vinegar thorn), Weinschierling (wine hemlock), Weinnäglein, (wine clove), Weinäuglein (wine eye), Kreuzdorn (cross thorn), and so on.
In French, besides the older berbere, and the form berberis, which is in common use to-day, we have épine-vinette, which Littré considers may have been given to the plant either because of its clusters of berries, resembling grapes, or because a sort of tart berry wine is made from them, or else because of its acidity, vinette being in many provinces the name of sorrels, sour grapes, and the like. This last supposition would make the name a counterpart of the German Sanerdorn.
The Spanish berberis and the Italian berberi do not, of course, call for any special explanation. Without attempting to make a complete list of the names which have been applied to this plant. enough have been given to show that, at least in the history of those forms cognate with our own barberry, there are presented not a few curious and perhaps significant analogies with the evolution of a group of organic species subjected to the diverse influences of changing environment.
Leaving now the matter of names, let us proceed to consider the plant itself, and, so far as may be, something of its history.
The barberry's place in Nature is expressed botanically by saying that it belongs to the principal genus of the family Berberidaceæ, and is thus near of kin to our native "twinleaf" (Jeffersonia), "cohosh" (Caulophyllum), and "May apple" (Podophyllum). As will be seen by referring to Fig. 3, the floral structure is, like theirs, notably simple and regular, and the parts are all distinct, thus recalling the general features to be found in the buttercup family (Ranunculaceæ) and the moonseed family (Menispermaceæ). It evidently is of the same ancestral stock as these, since they all agree so closely in fundamental plan, despite innumerable differences in matters of comparatively small detail. Moreover, the intense yellow color so generally characteristic of the tissues of Berberidaceæ, depending, as is well known, upon the presence of the bitter alkaloid berberine (C20H17NO4), occurs also to some extent in the families mentioned. Hence the structural evidences of consanguinity gain something of confirmation in the fact that we find the same substance which renders various species of Berberis useful for medicinal and tinctorial purposes imparting its tonic properties and intense yellow to the "goldthread" (Coptis) and "yellowroot" (Xanthorrhiza) among Ranunculaceæ, and the "calumba root" (Jateorrhiza) of Menispermaceæ.
In the old days of belief in "signatures," this yellowness of the barberry's tissues was taken as a sure indication that here must be a sovereign remedy for jaundice, and accordingly a decoction of the bark was in high repute as a specific for that disease. While this notion has, of course, long been banished to the limbo of imaginary medicine, yet, in the modern practice, decoctions, infusions, and the fluid extract of barberry bark, as well as the isolated alkaloid berberine, have a recognized tonic value. It is an aqueous extract prepared in India from the sliced roots and branches of the so-called "ophthalmic barberry" {Berberis lycium, and other Himalayan species, which constitutes the highly valued "rusot."
Considered from the plant's standpoint, this bitter principle, so abundantly present in its outer tissues, is doubtless to be regarded as a defense against gnawing animals, and as such, accessory to the spines which can be effective as a protection only against the larger animals which feed upon leaves. Thus, as often happens with the plants of our pharmacopœia, the very means adopted for its preservation becomes the object of its being destroyed for man's use.
But the barberry has more to contend against than the attacks of animals. As a native of regions visited by heavy storms of snow and wind, its branch system (often eight to ten feet in height), even though it be rid of its leaves through the winter, must, nevertheless, be subjected to a very considerable
Fig. 4.—Berberis vulgaris. Leafless branches, showing clusters of fruit and different forms of spines.
mechanical strain. A glance at the vegetative organs of our plant will show with what efficiency and economy of material this bit of engineering is accomplished.
First of all it will be noticed that there are two remarkably different sorts of branches (compare Figs. 1 and 4). The one sort, long, slender, and arching, are armed with the stout spines already referred to; while the others, originating from the axils of these spines, remain very short, although bearing year after year, through the summer, each a rosette of leaves. All who have observed the effect upon our trees and shrubs of one of those storms which load everything with snow and ice must have seen that the plants which received least damage were those in which there was either unusual stoutness of material or else such an attitude and flexibility in the branches as enabled them to bend readily under a load or other strain. Now, in the branch system of the barberry bush we find all these characteristics most happily combined; foi% thanks to the plant's economy in making the rosette branches so short, an abundance of material is available for the construction of those elongated ones which are to perform the special work of mechanical support.
In the course of its first year one of these elaborately organized shoots may attain a length of two feet or even more. During this rapid growth only a little wood is formed, but in the young bark there are developed about a dozen strands of tough, elastic fiber, which show as prominent ridges at the surface. These strands continue for a year or so to impart such strength and elasticity to the branch that when bent downward, even to a radius of two or three inches, it will spring back to its original curve. After the second or third year the bark and its fibers become brittle and weak through wear, but in the meantime the wood within, at first so meager, has been increasing, ring upon ring, around the central pith, so that, before the bark has ceased to be of mechanical service, there has already been formed to take its place a tissue possessing fully as much elasticity as the other, and in addition remarkable toughness and durability. These qualities are even more apparent as the wood grows older; so much so, indeed, that it is highly valued in turnery and the manufacture of archers' bows. Thus we see that when a storm comes, the barberry can meet the emergency with branches which yield gracefully so long as they are young, but with age become most effectively resistant.
Still, a moment's consideration of the distribution of strain will show that for all this flexibility and stoutness throughout the length of the branches a serious dismemberment of the plant must ensue if the place of juncture between each long branch and its trunk be not strongly re-enforced. Now, the long branches of the barberry arise each as a continuation of the axis of a rosette branch. While these short branches have only a cluster of leaves to support, they are but weak, brittle affairs, composed chiefly of soft pith with only a sparse supply of woody fibers; but when the short axis comes to serve as the basal part of a long shoot, not only does the wood increase remarkably, but even the pith becomes hard and firm. Moreover, we find throughout the whole plant that, whenever a branch is called upon to sustain a considerable load, its base is proportionately thickened and strengthened, and the same is true to a marked degree of the main trunk at its juncture with the root.
Although with us barberry bushes are for the most part denizens of the open, in Europe they are reported as often growing at the margin of woods. When in this situation, the branches become much more elongated, and, by using the recurved spines as grappling hooks, they climb over the shrubbery encompassing Leaves and the tree trunks, and finally gain support upon the branches of the trees themselves. Unlike ordinary vines, however, which only injure the plants that support them, the barberry may be of some service, as its armament of spines is well calculated to repel intruders.
The great aim of all this spread and strengthening of branch work is of course to secure the most advantageous exposure of foliage to light; to the attainment of this object the form and arrangement of the leaves themselves also contribute not a little. Wherever we find such rosettes of wedge-shaped leaves as the barberry produces, the likelihood of one leaf overshadowing its neighbor is much reduced, and when as in shady localities this matter is of special importance, it is a noteworthy fact that the leaves commonly adapt themselves to each other so perfectly that a cluster becomes almost equivalent to a single large shield-shaped blade. Moreover, on the more horizontal shoots the margins of contiguous rosettes dovetail into each other so neatly that the result may be justly compared to a mosaic of leaves.
Another peculiarity connected with that abbreviation of the branchlets which results in the rosette arrangement is the method of defoliation. When the time arrives, the leaves, instead of separating entirely, drop only the blade, while the flattened overlapping leafstalks remain attached to the stem and perform the function of bark for several years.
It will thus be seen that we have in the barberry one of those rare cases (paralleled by certain species of orange, grapevine, and creeper) in which an apparently simple leaf has the blade articulated with the stalk after the manner so characteristic of the leaflets of compound leaves (Fig. 8). Of the hundred or more known species of Berberis, about twenty (forming the subgenus Mahonia) have compound leaves of from three to many leaflets all plainly articulated at the base (Figs. 6 and 7), just as is also the case with certain species of the genera Citrus and Vitis, to which the orange and the grape respectively belong. Moreover, throughout the Berberidaceæ we find almost all the species to possess leaves which are obviously compound, the chief exception being those eighty species (forming the subgenus Euberberis) which in their leaves agree essentially with Berberis vulgaris. In view of these facts, botanists have been led to adopt the somewhat paradoxical theory that leaves of the euberberis type are in reality compound though unifoliolate.
The question as to how such a curious state of things could have come about is so closely connected with what concerns the evolution of the other vegetative organs that we shall do well to consider them all together.
In attempting to reconstruct for ourselves the main features of the original ancestral barberry we are much helped by the fact that besides Berberis vulgaris, which is the only representative of the genus in central Europe, there have been developed a multitude of species in Asia and a still larger number in the two Americas; for it is clear that this must considerably increase the chances of our being able to find something like the primitive form persisting in certain living species. Guided by the principle that evolution is for the most part attended by increase of differentiation,
Fig. 6. | Fig. 7. | Fig. 8. |
Fig. 6.—Berberis aquifolium. Quinquifoliolate leaf. | ||
Fig. 7.—Berberis trifoliata. Trifoliolate leaf. | ||
Fig. 8.—Berberis vulgaris. Unifoliolate leaf. A indicates the point of articulation of the leaflet. |
we may fairly assume that the branch system of the prototype differed from Berberis vulgaris in having the internodes approximately equal, thus making the lateral branches on the one hand and the main branches on the other more nearly of a length and all the leaves uniformly disposed in elongated spirals.
Such a condition is indeed tolerably well exhibited in the mahonias, as may be seen in the "holly-leaved barberry" (Fig. 5), which is a fair example of the Mahonia group. At the same time it is worthy of note that along with the greater uniformity of the branches is associated the possession of compound leaves having from three to many leaflets. This fact, taken in connection with the circumstance that almost all the other members of the family have the leaves more or less plainly of the palmate type, makes it probable that the ancestor of the barberries had trifoliolate leaves not unlike those often found interspersed among the larger leaves of the multifoliate mahonias and appearing also as the sole form on other species of the same subgenus (compare Figs. 5 and 7). It is significant, moreover, that the mahonias are without the highly developed spines so characteristic of the Euberberides, but depend for protection upon the spiny margins of their evergreen leaflets.
Thus, whether we consider the approach toward similarity among the branches, the approximation in the type of leaf to that most common in the family, or the absence of specialized spines, we are led to the conclusion that the Mahoniæ since they exhibit so much less differentiation than the Euberberides, must therefore represent more nearly the primitive features of the genus—a conclusion which is confirmed by such paleontological evidence as we possess. For the five species discovered in the Tertiary formation of southern France, northern Italy, and Switzerland are all mahonias, one of them (Berberis helvetica) closely resembling the American holly-leaved mahonia here figured, while others are like forms living at present in China. In view of these facts we shall probably be not far from the truth if we picture to ourselves the ancestral Berberis as being a small bush or underbrush resembling in a general way our evergreen holly, but having in place of each simple leaf a compound one of three leaflets. Almost exactly corresponding to this description is the already mentioned Berberis (Mahonia) trifoliata of Mexico and the adjacent regions.
That the ancestral home of the barberries was most probably in the northern part of North America appears from what is known of the geographical distribution of the species when viewed in the light of the generalizations arrived at by Bentham, Hooker, and Asa Gray regarding the origination of the members of the north temperate flora. We learn from Bentham that "to the great majority of them no primeval antiquity can be ascribed in central or western Europe; they appear to have come from the East, a considerable number perhaps from western Asia, where their types appear to be more varied, but many also must have made half the tour of the globe. Large American genera have sent out offsets into eastern Asia, which, gradually diminishing in number of species and sometimes slightly modifying their character, have spread over the whole of Asia, and invaded almost every part of Europe."[3] Of these latter genera Berberis is surely one.
Geologists tell us that the climate even of arctic America during the Mesozoic era was as warm and equable as that of our Southern States to-day. The same was true of northern Europe and Asia, and there is good reason to believe that between the latter and America there was during Mesozoic times a continuous land connection in high latitudes, or at least a chain of islands uniting the two continents. Such were the conditions then under which we may suppose a berberidaceous herb to have acquired the shrubbiness and other characteristics which distinguish barberries from the rest of the family.
As the descendants of this trifoliolated, woody form multiplied and spread over the vast territory open to them, the modifications which arose must have progressed along two principal lines of development. The first to diverge was doubtless the line of pinnate-leaved mahonias. To explain the development of such a leaf from the trifoliolate ancestral form, we have only to suppose the terminal leaflet to become stalked and then divided into three, just as we must conceive the trifoliolate leaf to have been derived in the first place from a sessile, simple-bladed one. From such trichotomy of the terminal leaflet would result a five-foliolated leaf (Fig. 6); but let the process be repeated with successive terminal leaflets a sufficient number of times, and the most highly developed mahonia leaf is readily accounted for. This view accounts, moreover, for the curious circumstance that in these leaves there is, in addition to the articulation between leaflet and rhachis, a transverse articulation extending across the rhachis between each pair of leaflets (Fig. 6 A). For what can this be but the representative of that terminal articulation which was once at the base of a leaflet since differentiated into all those parts of the leaf now lying above the articulation?
Along with the multiplication of leaflets there appears to have been a lessening of the number of leaves and some shortening of the branches, which affected the lateral ones somewhat more than the primary axes; but beyond this the changes introduced concerned only matters of small detail. The descendants of this new form spread into Asia and thence into Europe, where we find some remains of them in the deposits of the Tertiary. Subsequently, in the course of that general lowering of temperature which culminated in the Glacial period, these pinnate-leaved species were exterminated in Europe, while in Asia and America, where a more southerly extension into warmer regions was possible, they were able to survive and spread northward again after the retreat of the glacier and so take up their home in the localities we find them to-day. That such a form as Berberis trifoliata, which retains so fully the primitive characteristics, should remain in Mexico, seems to find a sufficient explanation in the fact that the climate of this region resembles most closely that of its supposed northern home in preglacial times; or, in other words, we may look upon the persistence of the original form as connected with the continuation of similar climatic conditions during the life of the species from the time when the genus first appeared.
While the ancestors of our modern mahonias were seeking an asylum in lower latitudes, certain other descendants of the primitive trifoliolate barberry were in all probability enabled to hold their own much longer against the encroaching cold, by developing those adaptations to extremes of temperature which make the various forms of euberberis so well suited to their present home.
We have already seen the advantages which come with differentiation of the branch system when plants are to be subjected to the storms of a severe winter. Such differentiation, however, means not only a more efficient disposition of the mechanical elements in the stem part of the plant, but it involves a closer and closer crowding of the leaves on the shorter branches until the limit of crowding is reached in the rosette. Obviously trifoliolate leaves are ill suited for such an arrangement—the lateral leaflets would be so much in the way. The causes which bring about the reduction and final disappearance of parts that have become useless or harmful to a species could not fail, therefore, to affect these leaflets until the present unifoliolate condition was reached. Moreover, in the absence of lateral leaflets there would be less need for an elongated leafstalk, and we should expect, therefore, just such an abbreviation of this organ as we actually find in a large share of the species of euberberis. We have already noticed how this enables Berberis vulgaris to turn its petioles to good account, by keeping them as protective bark scales long after the leaf blades have fallen.
It is in harmony with our conclusion that the ancestral barberry was a holly-like plant, whose descendants became modified under the influence of gradual refrigeration, to suppose that the earlier forms of euberberis were evergreen. So far as their migrations enabled them to continue living under conditions of climate favorable to the retention of leaves throughout the year, this habit might be expected to be present. This we find is the case with species in central Asia and in the mountainous and temperate parts of South America. Even in a region of much snow and ice no serious disadvantages need be feared, provided the plant does not extend its branches far above the ground. This will doubtless explain the presence of the evergreen mahonia undershrubs in our Western States, as well as other apparent exceptions among Berberides to the general principle we are now applying.
Along with the firm texture belonging to evergreen leaves there would naturally be retained the marginal spines which protected the mahonia ancestors from browsing animals. But with the establishment of the rosette arrangement the leaves which are borne by a long shoot, in virtue of their position just below the rosettes, come to have a special importance in this protective capacity. For, in the first place, as being already fully developed at a time when the rosette leaves are young and tender, the old leaves can shield the newer ones at the most critical period of their life; and, in the second place, given one stout, spiny leaf in such intimate connection with the mature cluster, and the need for using up material in spinemaking for the latter is much lessened. Accordingly, we find very generally throughout the evergreen Euberberides, along with the differentiation of the branches into long and short, a differentiation of the leaves—those subtending the clusters being decidedly spiny, while those of the cluster are less strongly armed. A particularly good example of such differentiation not far advanced is afforded by a species growing in Chili (Fig. 9). In a number of cases, such as the "box-leaved barberry" (Berberis buxifolia, Fig. 10), the differentiation has been carried so far that the subtending leaf has been completely transformed into a formidable spine, while the rosette leaves have lost all trace of spines except at the tip.
After the plurifoliolate and the unifoliolate types of evergreen barberries had been evolved there was the further possibility of developing from the latter a yet higher type which should be still better adapted to meet the exigencies of a severe and snowy winter, and at the same time safely attain a considerable height. All this would follow from the acquirement of the deciduous habit.
In the series of forms which came to adopt the expedient of defoliation at the approach of winter, several causes may have conspired to bring about in the two sorts of leaves a still further specialization of the two functions of assimilation and defense, which, originally combined in each leaf, began, as we have seen, to be separated more or less in the evergreen Euberberides.
As regards the subtending leaves, not only would their importance as a defense to the young rosette be sufficient to insure their persistence through the winter, but the same reason which. made the defoliation of the rosette advantageous—namely, decrease of the surface on which snow might lodge—would favor a reduction of lateral spread in the persisting leaf blades. Moreover, assimilation could not, of course, be carried on during the winter, and so the green parts of the leaf could well be spared to afford the material necessary for making the spines firmer and longer. Thus would finally result a purely defensive organ, so much the more efficient because having no other function to perform. Our common barberry exhibits especially well (Figs. 11 and 4) not only the more highly developed spines, but the intermediate stages connecting these with the primitive spiny leaf. Toward the tip of the uppermost shoots we find slender, one-pronged spines; the next below these are three-pronged, while those toward the base of the same shoot may have the prongs five or more in number. Passing now to one of those shoots, known as "suckers," which spring from older (mostly subterranean) parts of the plant, we find in addition to the forms of spines already noticed, others (Fig. 11, A-D) in which foliar characteristics become more and more evident as we approach the base of the shoot, where occur spiny leaves (A) essentially like what we have assumed to be the ancestral form. In regard to the position which these different forms occupy in relation to the ground or to their proximate basis of support, it is worthy of note how nicely all this accords with the theory of their having been developed under the influence of snowy winters.
To the rosette leaves the limiting of their duration to the warmer part of the year would permit a much thinner texture than was formerly necessary, and in consequence a more extended spread. This would of course involve a corresponding weakening of the marginal spines, but these being now so fully superseded in function, might safely be reduced to such slender cilia as we now find on the leaves of our common barberry (Fig. 8), or indeed be done away with altogether, as not infrequently happens in the same plant. They are clearly rudimentary organs tending to disappear.
A further consequence of the increasing severity of climate was the need of some special means to protect the tender organs of the bud against harmful changes of temperature. So long as these changes were comparatively slight and one set of leaves remained in place while the others were developing, the sheathing bases of the former served as a loose protective covering which answered every purpose. This supplementary function obviously fell to the lot of the last-formed or uppermost leaves of the set. As need arose for better protection of the infant shoots, the simplest way of meeting it would be to increase the efficiency of the parts already in use by widening them as far as might be necessary. As this was going on, the same fate which overtook the lateral leaflets of the original three would now extend to the terminal one of each of these upper leaves; for with the shortening of the stem they would be brought to lie so closely above the others as to shade them injuriously if not reduced in size. Moreover, as being the latest to develop, they would get but a small share of the reserve food provided for the rosette. Still, their relation to the supply of nutriment as well as their uselessness or power for harm in the rosette would, after all, be more a matter of degree than in the case of the lateral leaflets, since these latter would have to lie practically in one plane and so must interfere not only with the terminal leaflets but with each other. This may help us to explain why, although the lateral leaflets have so entirely
Fig. 11.—Berberis vulgaris. Series of spiny leaves passing into spines.
disappeared, we still find on some of the lower bud scales traces of a blade which thus afford connecting links in our morphological chain (Fig. 13).
This evolution of the bud scales must, of course, have been closely connected with that shortening of the petiole which we have already noticed in the typical rosette leaves as having culminated in the production of persistent overlapping scales forming an outer bark for the secondary branches; and it would seem most probable that the development of bud scales and bark scales proceeded side by side. Finally, as accounting further for their similarity of form, it may be remarked that in both, the protective function, at first merely incidental to that of mechanical support, comes at length to be the sole use for which they are retained: in one case it is a matter of years, in the other of generations.
For the propagation of barberries gardeners often take advantage of those adventitious shoots or "suckers" before mentioned which spring from near or beneath the surface of the ground. These, separated from the parent and planted in suitable soil, strike root after the manner of a willow twig and develop into a shrub. With wild barberries, if the main part of the shrub happens to be fatally injured, suckers proceeding from parts of the root even remote from the stem may continue to live and thus perpetuate the stock in the same locality.
In Nature, however, it is upon seedlings that the chief dependence is placed for the continuance and spread of the species. Having now considered, as fully as present limits will permit, the phenomena connected with the barberries' vegetative life, we will next turn our attention to the special peculiarities of flower and fruit which contribute more or less directly to the production and care of offspring.
[To be concluded.]