130 ANACARDIACEiG. Rhus. 



4. Rhus venenata, DC. Poison Sumach. Poison Elder. 



Young branches and petioles smooth; leaflets 7-13 (membranaceous), obovate-oblong, 

 entire, abruptly acuminate ; panicles slender, in the axils of the uppermost leaves ; drupes 

 nearly globose, smooth, greenish-white. — DC. proJr. 2. p. 68 ; Hook.Jl. Bor.-Am. 1. p. 127 ; 

 Darlingf. jl. Cest. p. 207; Torr. <^ Gr. fl. N. Am. 1. p. 218. R. Vernix, Linn, (in part); 

 Michx.fl. \.p. 183; Pursh,fl. l.p. 205; Ell. sk. l.p. 362; Bigel. med. hot. I. p. 96. t.lO, 

 and fl. Bost. p. 1 19 ; Torr. fl. I. p. 323. 



A shrub 10-18 feet high, branching above ; the young branches a little verrucose. 

 Leaflets l| - 3 inches long, abruptly contracted at the base, smooth, or sometimes slightly 

 pubescent underneath : common petiole often of a purplish color. Flowers greenish, in long 

 loose panicles ; pedicels pubescent. Fruit dry, about the size of a small pea, shining. Nut 

 orbicular, ribbed. Cotyledons oval, rather thick and fleshy. 



In swamps : common. Fl. June. i^A September. 



This is a violent poison to many persons ; a contact with the plant, or sometimes its mere 

 effluvium, causing a most painful eruption on the skin. The greater number of persons, 

 however, who handle or approach the plant, are unaffected by it. One of the best applications 

 in cases of poisoning by this and the following species, is a solution of sugar of lead, to be 

 applied after the use of saline cathartics. This treatment has been very successful in the 

 hands of Dr. Knieskem. The North American plant was formerly considered as identical 

 with i?, Vvrnix '(now called R. vernicifera) of Japan, especially as it yields a varnish like 

 that species ; but it was at length found to be distinct. 



5. Rhus Toxicodendron, Linn. Poison Oak. Poison Vine. Me7-cury. 



Stem erect, decumbent, or climbing by radicles ; leaves trifoliolate, somewhat pubescent 

 underneath ; leaflets (membranaceous) broadly oval or rhomboid, acuminate, entire or toothed, 

 the lateral ones unequal at the base ; panicles racemed, axillary, nearly sessile ; fruit nearly 

 globose, smooth.— M/:c7ia:>./ l.p. 183; Torr. fl. I. p. S23; Torr. <^ Gr.fl. N. Am. I. p. 218. 

 R. Toxicodendron aiid radicans, Linn., Nutt , DC. prodr. 2. p. 70. 



var. 1 : not chmbing ; leaflets entire, or variously and irregularly toothed or lobed. — Torr. 

 <^- Gr. I. c. R. Toxicodendron, Linn., Nutt. I. c. <^c. R. Toxicodendron, j;er. quercifolium, 

 Miclix. I. c. ; Pursh, fl.l. p. 205. 



var. 2 : climbing ; leaflets entire, or sometimes slightly toothed. — Torr. <^- Gr. I. c. R. 

 radicans, Linn.; Bot. mag. t. 1806 ; Ell. sk. I. p. 363 ; Bigel. med. bot. 3. p. 19. t. 42, and 

 fl. Bost. p. 120; DC. I. c; Darlingt. fl. Cest. p. 207. R. Toxicodendron, var. radicans, 

 Torr. fl. I. c. 



The upright variety, a suff"ruticose plant 1-2 feet high ; tlie other, climbing from 5 to 40 

 feet high, its woody trunk (sometimes 2 - 5 or 6 inches in diameter) furnished with in- 

 numerable dark-colored rootlets, by which it adheres to trees and other objects. Leaflets 

 2-5 inches long, pubescent when young ; lateral ones sessile, terminal one on a partial 



