IRRITANT POISONS 81 



RHUS TOXICODENDRON {N. America). 151. 



POISON IVY — TRAILING POISON OAK. 



Anacardiacece. — A shrub; climbing by rootlets over rocks, 

 etc., or ascending trees. — Flowers greenish-yellow, in loose, 

 slender, axillary panicles; June. — Leaves alternate, simple; 

 leaflets 3; rhombic, ovate, mostly pointed, rather downy 

 beneath, variously notched, sinuated, or cut-lobed. — Stem 

 contains a milky juice. 



Toxic Principle.— TOXICODENDROL. 



Arteris atque hedera procera adstringetur Hex. 



Horace: " Epode" xv. 



RHUS VENENATA. 

 RHUS VERNIX {N. America). 152. 



POISON ELDER — POISON ASH — POISON SUMACH — SWAMP 

 SUMACH — DOG WOOD. 



Anacardiacece. — A hardy, deciduous tree. 6-18 ft. — Flowers 

 green, small, polygamous, in loose and slender, axillary and 

 bractate, terminal panicles. Calyx 4-6 parted, persistent; 

 petals 4-6, much spreading, imbricated; stamens 4-10; July. 

 — Fruit in small, dry, compressed drupes. — Leaves alternate, 

 simple; leaflets obovate-oblong, entire, rather glabrous than 

 pubescent, reticulately veined below, veins above red-purple, 

 becoming red on decay. — Stem contains a milky juice. 



Toxic Principle.— TOXICODENDROL, also contained in 

 R. arborea, R. caustica, R. diversilobaj R. metopium, R. radi- 

 cans, R. coriaria. 



As knops that stud some cUmug to the pith 

 Pricked for gxLm. 



Browning: " SordeUo.'' 



