Soiacii, Or Snmac (Arab, summak), the common name for plants of the genus rhus (the ancient Greek and Latin name), of the cashew family or anacardiacece, which includes, besides the cashew, the mango and other tropical fruits. The sumachs are represented in the United States by about 12 species, which are shrubs or small trees, with alternate, sometimes simple, but generally trifoliolate or odd-pinnate leaves, and small polygamous flowers in terminal or axillary panicles; the sepals and petals are five, and the stamens, also five, are inserted under the margin of a disk which lines the calyx; fruit a small, dry, nut-like drupe. Our species are separable into several well marked sections or subgenera. 1. The sumachs proper, with pinnate leaves, flowers in a terminal crowded panicle, and the globular fruit clothed with acid hairs; the plants not poisonous, and containing an abundance of tannin. The smooth sumach (rhus glabra) is the most common, often covering extensive tracts of barren soil; it grows from 2 to 12 ft. high, with leaves a foot or more long, consisting of 11 to 31 lance-oblong, pointed, serrate leaflets, which are whitish beneath; the yellowish green flowers appear in June, and are pleasantly fragrant; the fruit, in dense clusters, is of the richest crimson, with a velvety appearance from the number of small hairs; it has a pleasant acid taste, due to the presence of a great abundance of bimalate of lime; an infusion of the berries is sometimes used to make a cooling drink in fevers, and as a gargle in affections of the throat and mouth.

The leaves of this species are among the first which put on autumn colors, and show fine tints of yellow and scarlet; a variety in which the leaflets are much subdivided, discovered some years ago in Pennsylvania, is in cultivation for the fern-like beauty of its foliage under the name of cut-leaved sumach. The stag's-horn sumach (R. typhina) is the largest of the northern species, sometimes reaching 30 ft., hut is usually about 10 ft.; it is readily distinguished from the preceding by the copious soft velvety down which clothes the ends of the branches; the wood and abundant pith are yellowish or orange-colored; the clusters of fruit, at first crimson, turn purple in autumn; they have the same acid properties as the foregoing. The dwarf or mountain sumach (R, copallina) is a remarkably neat shrub, seldom more than 6 or 8 ft. high; the branches are downy, but less conspicuously so than in the stag's-horn sumach, and it is readily distinguished from either of the others by its dark shining leaves, the common petiole to which bears a winged margin; the leaves in autumn turn to a rich purple; fruit similar to the preceding.

A very dwarf species of this section, R. pumila, with branches only about a foot high, is found from North Carolina southward in pine barrens; this has been erroneously described as poisonous. 2. The section lobadium includes species in which the flowers are in short ament-liko spikes preceding the leaves, fruit flattish, and leaves of three leaflets, not poisonous. The principal species is the fragrant sumach (R. aromatica), a straggling bush 4 or 5 ft. high; its range is from Vermont to Florida, and westward to the Rocky mountains, where it has smaller leaves and has been described as a distinct species (R. trilobata). The leaves of the eastern form are pleasantly fragrant when bruised, and those of the western have a strong and heavy odor; they with other leaves form the kinni-kinick or killikinick, smoked by the Indians as a substitute for tobacco. 3. The section cotinus has simple leaves, not poisonous, and flowers in loose paniclos. This is represented by the well known Venetian sumach, or smoko tree of the gardens (R. cot inns), sometimes called by nurserymen the purple fringe tree; it is a native of southern Europe, and is rarely over 10 or 12 ft. high; in summer it is nearly enveloped in large, feathery, cloud-like masses, which are at first greenish and later tinged with red; this very showy effect is produced by the little pedicels or stalks of the flower cluster, very few of which bear flowers and fruit, while the abortive ones lengthen greatly, branch, and become plumose with long hairs.

This plant was known to the ancients, and has long been used in Greece and other countries for tanning and dyeing. A tree closely resembling this, found in the interior of Alabama, and described by Nuttall as a distinct species (R. cotinoides), is so little known that it is not yet admitted as really different. 4. The toxicodendron group includes two species with white or dun-colored berries in loose panicles and highly poisonous foliage. The poison ivy or poison oak (R. toxicodendron) is also in some localities called mercury vine; it has leaves of three leaflets, which are rhombic ovate, and variously notched, lobed, or even entire; its flowers are in loose slender axillary panicles; the smooth fruit is pale brown. This is found nearly all over the country, especially in moist and shady places, and presents two forms, one erect and the other climbing, which were formerly described as distinct species, but run into one another in such a manner that they can hardly be regarded as varieties; it clambers over rocks and fences, and by means of aerial rootlets ascends the trunks of the tallest trees, and adheres with great pertinacity; when wounded it exudes a milky juice, which becomes black upon exposure to the air, and upon fabrics makes a stain indelible by all ordinary solvents; the leaves taken internally promote the secretions of the skin and kidneys.

This plant is highly poisonous to many persons. The poison sumach (R. venenata), also often called poison dogwood and poison elder, is an exceedingly neat and graceful shrub, G to 18 ft. high, found in swamps from Canada to Louisiana; the young shoots are purple, or green clouded with purple, and marked by orange-colored dots which turn grayish'; the leaves have 7 to 13 leaflets, which are dark green, pointed, and entire on the margins; the greenish yellow flowers are in loose axillary panicles, and the greenish white fruit hangs in loose clusters on stems 6 or 8 in. long, and remains after the leaves have fallen; the juice is milky, and dries to a black varnish. This has poisonous characters similar to the preceding, but is much more virulent. The susceptibility to the poison varies greatly in different persons; many can handle the plants without any unpleasant results, while others are seriously affected by touching them, or even passing near them. The poisonous properties of these plants are due to a volatile acid named by its discoverer, Prof. J. M. Maisch, toxicodendric. Its effect is an acute eczematous inflammation of the skin, often accompanied by much swelling. The usual remedies are cooling saline purgatives and an external application of lead water.

The coral sumach (R. metopium), a native of the West Indies, is found in the southernmost parts of Florida; it is a tree 15 to 20 ft. high, with leaves of three to seven thick leaflets, and loose clusters of scarlet berries the size of peas; this also is poisonous. - The sumach of commerce formerly consisted entirely of the imported leaves of rhus coriaria of southern Europe and northern Africa; it greatly resembles in appearance our stag's-horn sumach (R. typhina), and like that forms a small tree; it is largely cultivated in Sicily, where the suckers are planted in rows about 4 ft. apart, and the shoots are yearly cut back to within a few inches of the ground, the crop for the next year being furnished by the new stems which push from the stumps; the shoots are dried and threshed, the leaves are finally ground between mill stones and bolted, and the powder is put into sacks of 1G3 lbs. each for shipment; the product is sometimes adulterated with other leaves, but when pure contains from 30 to 35 per cent, of tannin. Sumach is used for tanning light-colored leathers and in dyeing and calico printing; it yields with different mordants a great variety of tints.

Since the civil war the collection and preparation of the leaves of our native sumachs have assumed considerable importance, especially in Virginia, the headquarters of the industry being at Rich-mond. The plants grow so abundantly in the wild state that cultivation has not been attempted; the smooth, the stag's-horn, and the mountain sumachs are collected indiscriminately, but as the first named is the most abundant, the product consists mainly of that; the gathering begins early in July and continues till frost. The leafy tops of the plants are broken off and carefully dried, the best being that dried in the shade; when dry it is beaten with sticks, and the leaves are taken to the mill to receive the same treatment as that described for Sicilian sumach. American sumach contains from 15 to 20 per cent, or more of tannin. - The Japan wax, or vegetable wax of Japan, is yielded by rhus succedanea, being found as a thick white coating of the seed within the capsule. To extract it, the bruised seed vessels are boiled in water and the wax skimmed off as it rises to the top; it has much the appearance of white wax (bleached beeswax), but is rather more opaque; it melts at about 127°, saponifies readily, and formed into candles gives a fine clear light; mixed in proper proportions with paraffine, it makes a candle in appearance closely resembling one of wax. - The lacquer of the Japanese is produced by R. vernicifera, a shrub so nearly like our poison sumach in appearance and in poisonous qualities that the two were at one time supposed to be identical.

The juice, obtained by wounding the tree, is at first milky, but becomes black on exposure, and is largely used for furniture and various kinds of woodwork. Americans in Japan have become seriously poisoned by coming in contact with newly varnished wares. Dr. Jacob Bigelow many years ago demonstrated that our poison sumach affords a similar product. Other and poisonous species afford lacquer to the natives of China and India. - The singularly shaped Chinese galls are the result of the puncture and deposition of the egg of an insect in the leaf stalks and young shoots of a sumach, rhus Semialata, of northern India, China, and Japan; the galls are very irregular in shape, 1 to 2½ in. long, mostly egg-shaped, with various knotty protuberances, and often lobed, velvety with a gray down; they are mere brittle shells about 1/20 in thick, breaking with a shining fracture, and containing about 70 per cent, of tannin. In 1872, 8,621 cwt. of these galls were imported into Great Britain alone.

Smooth Sumach (Rhus glabra).

Venetian Sumach (Rhus cotinus). Fruitful and abortive pedicels, reduced and of full size.

Poison Ivy (Rhus toxicodendron).

Poison Sumach (Rhus venenata).

Chinese Galls (Rhus semialata).