10 
SILVA OF NORTH AMERICA. ANACARDIACEE. 
The juice of this plant, which 
An infusion of 
of cutaneous diseases. Their medicinal worth, however, is not great.) 
turns black on exposure to the air, may serve as indelible ink ; it is soluble in ether.’ 
the astringent bark of the roots of Rhus aromatica? an undershrub widely distributed through the 
northern states and Canada, is valued as an excitant to the bladder, and in the treatment of hemorrhages 
and of atonic diarrhea.‘ The white waxy exudation produced in summer from the fruit of thus 
obovata,® a shrubby species of the mountains of southern California and the adjacent regions of 
Mexico, has a sweet and agreeable flavor, and is used by Indians as a substitute for sugar.° 
Few species of insects’ are known to injure Rhus in North America; and its diseases caused 
by fungi® are not numerous or particularly serious. 
Several species of Rhus, particularly the Sumachs of eastern North America, have long been grown 
in gardens for the beauty of their fruit and of their foliage which assumes brilliant colors in autumn. 
The Asiatic Rhus semialata is cultivated in the gardens of the United States and Europe for its 
conspicuous flower-clusters and its large handsome leaves which turn orange and scarlet before falling. 
Rhus lucida,’ a native of southern Africa, is often employed as a hedge plant in the countries adjacent 
to the Mediterranean.” 
The name of the genus, formed from ‘Pois, the classical name of the European Sumach, was 
established by Tournefort " and afterwards adopted by Linnzus. 
1 Stillé & Maisch, Nat. Dispens. ed. 2, 1436.— U. S. Dispens. 
ed. 14, 906. 
2 The juices of Rhus Toxicodendron, and even the effluvium ex- 
haled by it under the influence of a hot sun, are extremely poisonous 
to some persons, while others are not affected by them and can 
handle the plant without injury. The effects of the poison, which 
appear several hours after exposure, are redness and violent itch- 
ing, followed by fever and a vesicular eruption which may be 
accompanied, especially on the face and genitals, with tumefaction ; 
they reach their height on the fourth or fifth day, when desquama- 
tion begins and the swelling and pain subside. Herbivorous ani- 
mals are particularly fond of the leaves of R. Toxicodendron and 
devour them greedily and with perfect impunity; and various 
insects which feed upon them do so, apparently, without injury. 
(J. C. White, Dermatitis Venenata, 31.) 
8 Aiton, Hort. Kew. i. 367.—Gray, Gen. Jil. ii. 160, t. 160; 
Man. ed. 5, 112. 
R. Canadensis, Marshall, Arbust. Am. 129. — Watson & Coulter, 
Gray’s Man. ed. 6, 119. 
4 Napheys, Medical Therapeutics, 467. — Parke, Davis & Co., 
Organic Mat. Med. 154. 
5 Watson, Proc. Am. Acad. xx. 358. 
Styphonia integrifolia, Torrey, Pacific R. R. Rep. vii. pt. iii. 9, t. 2 
(in part). 
R. integrifolia, Brewer & Watson, Bot. Cal. i. 110 (in part). 
6 C. R. Orcutt, The Western American Scientist, iii. 46. 
7 The Jumping Sumach-beetle (Blepharida rhois, Forster) is one 
of the most troublesome insects which attack Rhus in North Amer- 
ica, often defoliating R. glabra and R. typhina over large areas of 
country. (C. V. Riley, 6th Rep. Insects of Mo. 118.) Caterpillars 
of various species feed on the leaves, and a leaf-roller (Lozotenia 
rosaceana, Harris) frequently disfigures them. An aphis (Pemphi- 
gus rhois, Fitch) causes the large conspicuous galls which often 
appear on the leaves of R. typhina, and Psylla rhois, Fitch, is 
sometimes found in great numbers on the different species, espe- 
cially on R. copallina. 
8 Most of the fungi inhabiting Rhus in North America are small 
species of the order Discomycetes found on the stems and less 
frequently on the leaves. The most conspicuous of these in the 
northern and eastern parts of the country is T'aphrina purpurascens, 
Robinson ; it is most abundant on Rhus copallina, but also attacks 
R. glabra. The diseased leaves, which are principally near the tips 
of the branches, may at once be recognized by a dark lurid pur- 
The 
affected leaflets are abnormally swollen and crisp on the upper 
The effect 
produced by this fungus is very unsightly, and might, without 
ple color becoming somewhat glaucous as the spores ripen. 
surface, and finally hang drooping from the branches. 
the aid of a microscope, pass for the work of insects. Uromyces 
brevipes (B. & Rav.) is found throughout the eastern and central 
parts of the United States on R. Toxicodendron and occurs in 
Pileolaria effusa (Peck), a closely 
related species, is found on R. aromatica, and other related forms 
afflict different species of Rhus in Japan. 
® Linneus, Spec. 267. — Cavanilles, Icon. ii. 27, t. 182. — Harvey 
& Sonder, Fil. Cap. i. 517.— Engler, De Candolle Monogr. Phaner. 
iv. 413. 
10 Naudin, Manuel de I’ Acclimateur, 463. 
11 Jnst. 611, t. 381. 
California on R. diversiloba. 
