CHAP. XXXVIII. ANACARDIA‘CEA. RHU'S. 555 
duced into England in 1697, and is occasionally to be met with in collections. 
There are good plants of both the species and the variety in the arboretum of 
Messrs. Loddiges. Plants of the species, in London, are 1s. 6d. each, and 
seeds ls. an ounce; at New York, 374 cents a plant. 
 & 10. R. rapi‘cans L. The rooting-branched Rhus, or Sumach ; or 
Poison Oak. 
Identification. Lin. Spec., 381.; Dec. Prod., 2. p.69.; Don’s Mill, 2. p. 71. 
Synonymes. R. Toxicodéndron var. a Michx. Fl. Bor. Amer., 1, p. 185.; and R. T. var. B Torrey 
Fl. U. S., 1. p. 322. 
Engravings. Big. Med. Bot., t. 42. ; and our jig. 230. 
Spec. Char.,§c. Leaf of one pair of leaflets and an odd one, the odd one 
upon a petiole; all glabrous and entire. (Dec. Prod., ii. p. 69.) Anative of 
North America. De Candolle has characterised three forms of this species 
as follows : — 
& R.r. 1 vulgaris. — Stem climbing by means of roots emitted from it ; 
leaflets large, ovate. &. Toxicodéndron vulgare Ph. Fl. Amer. 
Sept., 1. p. 205.; Bot. Mag., t. 1806.; Toxicodéndron vulgare, and 
T. volubile M//. Dict. This often poisons upon mere touching. 
& R. 71. 2 volibilis—The stem climbing, scarcely emitting roots; the 
leaflets large and ovate. Toxicodéndron volubile Mill. Dict. 
4 R.r. 3 microcérpa.—Leaflets oblong-oval with a tapered long point ; the 
fruit much smaller than that of the other forms. R. Toxicodéndron 
microcarpon Ph. F/. Amer. Sept.,i.p.205. There isa figure of this 
in Dill. Elth., t. 291. fig. 375. A plant of this variety in the garden 
of the London Horticultural Society was, in 1834, 4 ft. high, after 
having been 8 years planted. 
Description, §c. This species,in America, has 
a low shrubby stem, and forms a bush from 2 ft. 
to 3 ft. in height, whence shoots proceed near 
the bottom to the distance of 20 ft. or 30 ft. 
on each side, rooting at the joints, and com- 
pletely occupying the surface of the ground, 
Placed near a wall or a tree, the shoots climb 
up, and root into the joints of the wall, or 
into the furrows of the bark of the tree, ifthe @ 
latter should be old. It is a native of many 
parts of North America, from Canada to 
Georgia; sometimes covering the surface of 
the ground to a great extent; and at other times climbing to the top of the 
highest trees, and penetrating the bark with its fibrous roots. When the stem 
is cut, it emits a pale brown sap of a disagreeable scent; and staining so pow- 
erfully, that letters or marks made upon linen with it cannot be obliterated, 
but grow blacker the more the linen 1s washed, not being acted upon by com- 
mon chemical agents. (Churchill’s Medical Botany, vol. ii.) In Bigelow’s 
Medical Botany, it is stated, that the plant is as common in the woods of 
America as the ivy is in the woods of Europe; “ and the terrible effects of its 
poison are so frequent, that there seems to be no doubt on the subject. An 
American young man, who was cutting wood, had his feet, hands, and arms so 
dreadfully blistered by an unwary approach to this plant, that he could not 
work for some days.’ Kalm relates that the plant is poisonous to some 
persons, but less so to others, and that the same thing takes place with respect 
to it as with FR. venenata. (See p. 553.) He mentions the case of two sisters, 
one of whom could manage a plant of #. radicans without being affected by 
its venom; whilst the other felt its exhalations as soon as she came within a 
yard of it, or even when she stood to windward of it at a still greater dis- 
tance. Kalm says that the poison had not the least effect upon himself, 
though he tried it in various ways, and once squirted the juice into his eye; 
but that, on another person’s hand, which he had covered very thickly with 
it, the skin, a few hours afterwards, became as hard as a piece of tanned 

