young shoots and petioles usually of a fine red. Leaves pinnate ' 

 leaflets oblong or oval, entire, or somewhat slightly sinuated, acuminate' 

 smooth, paler underneath, nearly sessile, except the terminal one. 

 Flowers dioecious and polygamous, very small, green, in loose axillary 

 panicles. The panicles of barren flowers downy, largest and most 

 branched. Sepals 5, ovate. Petals 5, oblong. Stamens longer than the 

 petals, and projecting through their interstices. The rudiment of a 

 3-cleft style in the centre. In the fertile flowers, the panicles of which 

 are much smaller, the sepals and petals resemble the last, while the 

 centre is occupied by an oval ovary, terminated by 3 circular stigmas. 

 Fruit a bunch of dry berries or rather drupes of a greenish white, some- 

 times marked with slight purple veins, and becoming wrinkled when 

 old; roundish, a little broadest at the upper end, and compressed, 

 containing one white, hard, furrowed seed. The juice or even air 

 impregnated with the volatile principle of this plant is to many persons 

 a serious poison producing severe and dangerous erysipelatous swellings. 

 Kalm mentions a person who by the simple exhalation was swollen to 

 such a degree that " he was as stiff as a log of wood and could only be 

 turned about in sheets." Some constitutions are however but slightly 

 or not at all affected by it. 



589. R. Toxicodendron Linn, sp.pl. 381. DC. prodr. ii. 69. 

 S. and C. iii. t. 167. Bot. Mag. t. 1806. R. radicans Linn. 

 sp.pl. 381. Bigelow med. bot. iii. t. 42. DC. prodr. ii. 69. 

 Common in woods in the United States. (Poison ivy.) 



A creeping shrub with long cord-like shoots, emitting strong lateral 

 fibres. Leaves ternate, on long semicylindrical petioles. Leaflets 

 ovate or rhomboidal, acute, smooth and shining on both sides, the 

 veins sometimes a little hairy beneath. The margin is sometimes 

 entire and sometimes variously toothed and lobed, in the same plant. 

 Flowers small, greenish white. They grow in panicles or compound 

 racemes on the sides of the new shoots, and are chiefly axillary. The 

 barren flowers have a calyx of 5 erect, acute segments, and a corolla 

 of 5 oblong recurved petals. Stamens erect with oblong anthers. In 

 the centre is a rudiment of a style. The fertile flowers, situated on a 

 different plant, are about half the size of the preceding. The calyx 

 and corolla are similar, but more erect. They have 5 small, abortive 

 stamens, and a roundish ovary surmounted with a short, erect style, 

 ending in 3 stigmas. The berries are roundish and of a pale green 

 colour, approaching to white. Yields abundantly a yellowish narcotic 

 acrid milky juice, which becomes black when exposed to the air, and 

 forms an indelible ink when applied to linen. This juice, and even 

 the exhalations from the plant are extremely poisonous, to many 

 persons, though not to all. They bring on itching, redness and tume- 

 faction of the affected parts, particularly of the face, succeeded by 

 blisters, suppuration, aggravated swelling, heat, pain and fever. Symp- 

 toms though often highly distressing are rarely fatal. It is employed 

 in powder, infusion and extract internally in certain diseases. Dr. 

 Horsfield administered it with success in the dose of a teacup of the 

 infusion to consumptive and anasarcous patients ; it has been em- 

 ployed with supposed benefit in consumption, and is well spoken of in 

 cases of herpetic eruption, palsy, mania, and paralysis. 



De Candolle follows Nuttall in considering Rhus radicans and Toxi- 

 codendron distinct species; but I am persuaded that the supposed 

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