Rhus glabra. Smooth sumach.
Rhus Glabra. N. F. IV (U. S. VIII). Rhus Glabrum. U. S. 1870. Sumac Berries. Sleek. Scarlet. White Sumach. Shoe-make. Vinegar Tree. Sumac, Fr. Sumach, Gr.—"The dried, ripe fruit of Rhus glabra Linné (Fam. Anacardiaceae), without the presence of more than 5 per cent. of stems or other foreign matter." N. F.
Rhus glabra called variously smooth sumach, Pennsylvania sumach, and upland sumach, is an indigenous shrub from four to twelve feet or more in height. The leaves are upon smooth petioles, and consist of numerous opposite leaflets, with an odd one at the extremity, all of which are lanceolate, acuminate, acutely serrate, glabrous, green on their upper surface, and whitish beneath. In the autumn their color changes to a beautiful red. The flowers are greenish red, and disposed in large, erect, terminal compound thryses. The fruit is in clusters of small crimson berries.
The shrub is found in Canada and almost all parts of the United States, growing in old neglected fields, along fences, and on the borders of woods. The flowers appear in July, and the fruit ripens in the early part of autumn. The bark and leaves are astringent, and are largely used, especially the leaves, in tanning leather and in dyeing. The sumach for the manufacture of extract for tanners' use is largely cultivated in Virginia, where the annual crop reaches from 7000 to 8000 tons, and is collected at any time between the first of July and the appearance of frost.
The berries have a sour, astringent, not unpleasant taste, and are often eaten by the country people with impunity. They are described in the National Formulary IV as follows:
"Nearly globular, ovoid, more or less reniform, somewhat compressed, about 5 mm. in length and 2 mm. in diameter; externally dark red, velvety with short hairs, summit with remains of the short style, base occasionally with the five-cleft calyx and a short pedicel; endocarp, smooth, shiny, light red; one-celled, one-seeded; seeds dark brown, smooth. Inodorous; taste acidulous and slightly astringent. The powder is brownish-red, and, when examined under the microscope, exhibits irregular fragments; non-glandular hairs, more or less elliptical or ovoid or spatulate, about 0.15 mm. in length and from 0.045 to 0.08 mm. in width, filled with a pink or red cell sap in which occasionally occur rod-shaped crystals; glandular hairs with a short one-celled stalk and multicellular head, from 0.045 to 0.075 mm. in length; fragments of endosperm numerous; fragments of endocarp showing very small stone cells with irregularly thickened walls, readily determined by the use of aniline sulphate T.S. and sulphuric acid; fragments of embryo with rather small cells containing a fixed oil; occasional reddish colored fragments of epidermis and underlying spiral tracheae of the mesocarp. Mix 1 Gm. of powdered Rhus Glabra with 10 mils of hot water, shake the mixture occasionally until cold, filter, and allow the filtrate to evaporate spontaneously in a watch crystal; numerous, feather-shaped crystals separate which polarize light strongly with a distinct play of colors. Rhus Glabra yields not more than 4 per cent. of ash." N. F.
W. J. Watson ascertained that free malic acid and acid calcium malate coexist in the berries, which contain also, upon the same authority, tannic and gallic acids, fixed oil, extractive, red coloring matter, and a little volatile oil. (A. J. P., xxv, 194). A medicinal wine has been prepared from the fruit. (M. S. R., Feb. 9, 1867.) For a paper on the relative proportion of the constituents found in the husk and seed portion of the fruit by Frankforter and Martin, see A. J. P., 1904, 151.
Excrescences are produced under the leaves resembling Chinese galls in character, and containing large quantities of tannic and gallic acids. These have been used as a substitute for the imported galls by Walters of New York, who thought them in every respect preferable. They may be collected at little expense, as they are produced very abundantly, especially in the Western States.
Henry Trimble collected some galls from the leaves of R. glabra and found that they contained 61.70 per cent. of tannin, reckoned on the weight of the air-dried galls, or 70.90 per cent. of the weight of absolutely dry material. (A. J. P. 1890, p. 564.)
From the experiments of Stenhouse (A. J. P., xxxiv, 252), it appears that the tannic acid of sumach is identical with. that of galls, being, like it, resolved, under the influence of sulphuric acid, into glucose and gallic acid, and this change is supposed to take place spontaneously in sumach when long kept.
The percentage of tannin in Virginia, sumach rises at times as high as 27 per cent., but falls a few per cent. below this as the season advances. Samples of leaves gathered along the Mississippi near Dubuque, Iowa, in July and August, yielded 16.36 per cent. and 15.75 per cent. respectively. (A. J. P., 1888, p. 389.) The proportion of tannic acid in the European sumach falls from 6 to 8 per cent. below the percentage of the Virginia sumach, yet the European is much preferred by tanners and dyers. By using Sicilian sumach it is possible to make the finer white leathers so much used for gloves and fancy shoes, while by the employment of the American product the leather has a yellow color, apparently due to a coloring matter, which, according to Loewe, consists of quercitrin and quercitin, and exists in larger quantity in the American than in the Sicilian drug. Enormous quantities of a dark-red, semi-fluid, bitter, astringent extract are prepared in Virginia from sumach, and used both in America and in Europe. It is said to contain from 25 to 30 per cent. of tannin.
Recently the fruits of Rhus glabra have been replaced by those of the Stag Horn Sumac (Rhus typhina L.. This shrub is very abundant in the eastern United States. The fruits resemble those of rhus glabra both in form and size but are distinguished by being covered with needle-like crimson hairs which are frequently over 2 mm. long. For detailed description of the fruits of these two plants see Kraemer. (A. J. P., 1913, p. 398.)
Sumach berries are astringent and refrigerant. A strong decoction, or the fluidextract diluted, affords a very effective and pleasant gargle in angina, especially in combination with potassium chlorate. Fluidextractum Rhois Glabrae was official in the U. S. VIII, but then deleted. It was admitted to the National Formulary IV with a slight alteration in the menstruum. The fluidextract affords an excellent astringent in relaxing diarrheas and other conditions where the tannin drugs are useful. The dose of the fluidextract is fifteen to thirty minims (1-2 mils).