Part 5

While the “official” barks—that is, those that are recognized in the Eighth Decennial Revision of the United States Pharmacopœia—number only seventeen in all, twelve of which are furnished by trees and shrubs growing in the United States either as native or introduced species, there are many others which are nevertheless used in medicine to a considerable extent by one or another school of practitioners. All of the “official” barks are described in this bulletin, and an effort has been made to include such “nonofficial” ones as seemed to be most in demand, judging from the trade catalogues of wholesale dealers in crude drugs, but a number of others that are not so much used have been omitted on account of lack of space. The number of drugs fully described is thirty-five, but under many of the descriptions closely related species are also briefly treated.

Many factors have contributed to the destruction of our forests. Beginning with the settlement of this country, when land had to be cleared of timber to make way for homes, and on through the centuries there have been steady and increasingly heavy drafts upon our natural forest resources by an increasing population and the building up of various new enterprises, and until within very recent years with little or no thought for the needs and welfare of generations to come. In the collection of barks, too, may be seen another instance contributing in a measure to the depletion of our forests; for too often trees are felled and killed outright simply for the sake of obtaining the bark, or a tree is peeled to such an extent that death is certain to result. When it is considered that of cascara sagrada (Rhamnus purshiana) alone about 100,000 trees are annually sacrificed, and that the oak, pine, elm, birch, poplar, willow, and larch all contribute their quota of bark, it will be seen that at no very distant date more careful methods of bark collection and the replanting of now denuded areas will be needed. The Forest Service of the United States Department of Agriculture has issued Forest Planting Leaflets, giving full information in regard to the planting and propagation of many of our forest trees, and anyone interested in the subject can have these leaflets for the asking.

The statements herein regarding medicinal uses are based on the information contained in various dispensatories and other works relating to materia medica, and in a publication of the character of this bulletin can, of course, be referred to only in the most general manner. It is not the purpose herein to prescribe the use of any of these barks for medicinal purposes; such use should be made only under the direction of a physician.

The writer is indebted to Mr. George B. Sudworth, Dendrologist of the Forest Service, for an examination of the manuscript and for the use of a number of photographs taken by him and other members of that Service.

Other illustrations in this bulletin have been reproduced from photographs taken from nature by Mr. C. L. Lochman, and use has also been made of a number of illustrations found in the Handbook of the Trees of the Northern States and Canada, by Mr. R. B. Hough.

The writer also wishes to gratefully acknowledge information of various kinds furnished by wholesale drug dealers.

THE COLLECTION OF BARKS.

As with other medicinal portions of plants, the best time to collect the barks is at a period when the greatest quantity of the active constituents is contained therein. In the case of barks this is in early spring, before active growth takes place, or in late fall or even winter.

There are various methods of obtaining the bark. In some cases the outer corky layer is first shaved off before the bark is peeled, a process which is known as “rossing.” This is generally done where the outer layer is considered inert. Then incisions a few inches wide are made, and, depending upon the nature of the bark, sometimes strips several feet in length are peeled. The barks of some branches or roots are removed by making long, lengthwise incisions, permitting the bark to be readily slipped off, or in other cases the bark is first loosened by pounding with a mallet.

After collection, the bark is taken to a clean, well-aired place for drying, spread out on shelves or on the floor and protected from moisture. Barks contain less moisture and absorb less moisture than other parts of plants, but they nevertheless need to be protected from wet weather. Sometimes barks are strung on wires or strings to facilitate drying.

When the barks are thoroughly dried and have been broken or cut up into suitable lengths, they may be packed in dry, clean barrels or other proper containers ready for shipment.

It will be well to repeat here what has been said in the first of this series of papers, entitled “American Root Drugs,” with regard to the advisability of correspondence with crude-drug dealers previous to shipment, in order to ascertain whether a particular drug is desired, how large a quantity is wanted, and what price will be paid. Samples representative of the drug to be disposed of should be sent at the same time.

It is necessary also to emphasize the fact that the prices given in this bulletin are approximations only, being those paid at the present writing, and it must be remembered that before this bulletin is off the press a drug now listed at 10 cents a pound may have declined to 5 cents or less, while a drug quoted at 2 cents may be worth 5 or 10 cents or more. The object in noting prices is simply to give prospective collectors an idea of the range of prices, but with the constant fluctuations that take place in the drug market it will be readily understood that these prices can be but remotely approximate and that the actual price to be paid can be ascertained only through correspondence with drug dealers.

TREES AND SHRUBS FURNISHING MEDICINAL BARKS.

Each section contains synonyms and the pharmacopœial name, if any, the common names, habitat, range, descriptions of the tree or shrub, as well as of the bark as found in commerce, and information concerning collection, prices, and uses.

Bittersweet (Solanum dulcamara) is the only one of American medicinal plants of which the young branches alone are used, but it is nevertheless given a place with the barks, as it can more properly be included in this series than in any other.

WHITE PINE.

Pinus strobus L.

Other common names.—Northern pine, Weymouth pine, American white pine, American deal-pine, soft deal-pine, spruce-pine.

Habitat and range.—The white pine, indigenous to this country, occurs in woods from Canada south to Georgia and Iowa.

Description of tree.—This large, handsome evergreen tree—sometimes 200 feet in height and with a straight trunk measuring 3 to 4 feet in diameter—has horizontal branches, both trunk and branches covered with a smooth, grayish green bark when young, becoming dark and rough with age, and longitudinally fissured. The wood is soft and white, and much used for flooring, etc.

The slender, pale green leaves, or needles, are usually five in a sheath, about 3 to 5 inches long, the flowers rather inconspicuous, and the cones cylindrical, drooping, sometimes slightly curved, resinous, about 5 to 10 inches long and about an inch in thickness, but much wider after the scales spread apart, which generally occurs in September, allowing the seeds to fall out. (Fig. 1.) It requires two seasons for the cones to mature. The white pine belongs to the pine family (Pinaceæ).

Description of bark.—The inner bark of the white pine is the part employed medicinally. It occurs in flat pieces of irregular size, about an eighth of an inch in thickness, brownish on the outside, the inner surface sometimes lighter colored and sometimes darker than the outside, smoothish, and marked with fine grooves. It breaks with a tough, fibrous fracture, and has a slight turpentine odor. The taste is described as “mucilaginous, sweetish, bitterish, and astringent.”

Prices and uses.—At present collectors are paid from about 1/2 to 3 cents a pound.

White pine bark is used as an expectorant, forming one of the ingredients in the sirup which bears its name, which is much used for coughs and colds to facilitate expectoration.

TAMARACK.

Larix laricina (Du Roi) Koch.

Synonym.—Larix americana Michx.