Rhus. XXXllI. ANACARDIACEiE. 203 



2. R, TYPHlNA. Stag-horn Sumach. 



Branches andi petioles densely villous; Ifts. 6 — 15 pairs, oblong-lanceolate, 

 acuminate, acutely sei-rate, pubescent beneath; fr. red, with crimson hairs. — 

 A larger shrub than the former, attaining the height of 20f, in rocky or low 

 barren places, U. S. and Can. Stem with straggling, thick branches. Leaves 

 at length 2 — 3f long. Leaflets 2 — 4' long, i- as wide, sessile, except the termi- 

 nal odd one. Flowers in terminal, thyrsoid, dense panicles, yellowish-green, 

 often 9 c^ or Q $ c^. Drupes compressed, compact, the crimson down very 

 acid. Jn. — The wood is aromatic, of a sulphur-yellow, and used in dyeing. 



0. laciniata. — Lfts. very irregularly coherent and incised ; panicles partly 

 transformed into gashed leaves. Hanover, N. H. Rickard. 



3. R. copALi-iNA. Mountain Sumac. 



Branches and petioles pubescent ; lfts. 4 — 10 pairs, oval-lanceolate, mostly 

 entire, unequal at base, common petiole winged ; Jls. in dense panicles ; drupes 

 red, hairy. — A smaller shrub, not half the height of the last, in dry, rocky pla- 

 ces, U. S. and Can. Common petiole about 6' long, expanding into a leafy 

 margin, between each pair of leaflets. Leaflets 1 — 3' long, near | as wide, 

 dark green and shining on the upper surface. Panicles of flowers terminal, 

 sessile, thyrsoid, 9 cJ*) greenish. Drupes acid. Jl. 

 /?. leaflets coarsely and unequally serrate. N. Y. Barratt. 



4. R. VENENATA. DC. (R. vcmix. Linn.) Poison Sumac. Dog-wood. 

 Very glabrous; lfts. 3 — 6 pairs, oval, abruptly acuminate, very entire ; 



panicles loose, pedunculate; drupes greenish-yellow, smooth. — A shrub or small 

 tree of fine appearance, 10 — 15f high, in swamps, U. S. and Can. Trunk seve- 

 ral inches diam., with spreading branches above. Petioles wingless, red, 6 — 10' 

 long. Leaflets about 3' long, nearly ^ as wide, sessile, except the odd one. 

 Panicles axillary, 9 (^, those of the barren tree more difi'use. Flowers very 

 small, green. Drupes as large as peas. Jn. , The whole plant is very poison- 

 ous to the taste or touch, and even taints the air to some distance around with 

 its pernicious effluvium. 



* * Leaves ternate. 



5. R. Toxicodendron. Poison Oak. Poison Ivy. 



Erect or decumbent; Ivs. pubescent; lfts. broadly oval, acuminate, entire 

 or sinuate-dentate ; fls. in racemose, axillary, subsessile panicles ; drupes smooth, 

 roundish. — Can. and U. S. A small shrub, 1 — 3f high, nearly smooth in all 

 its parts. Leaflets 2 — 6' long, | as wide, petiolate, the common petiole 4 — 5' 

 long. Flowers small, 9 c?- Drupes pale brown. Poisonous, but less so than 

 the last. 



/?. radicans. Torr. (R. radicans. Linn, and of l5^ edit.) Poison Ivy. St. 

 climbing 3 — 20 or 50f ! by myriads of radicating tendrils. — It seems now gen- 

 erally conceded that this is but a variety. Certainly, if so, it is a very remark- 

 able one. In damp, shady places. Poisonous. 



G. R. AROMATicA. Ait. Swcct Sumac. 



Lfts. sessile, incisely crenate, pubescent beneath, lateral ones ovate, ter- 

 minal one rhomboid; fis. in close aments, preceding the leaves; drupe globose, 

 villous. — A small, aromatic shrub, 2 — Of high, in hedges and thickets. Can. and 

 U. S. Leaflets I 2' long, J as wide, sessile, the common petiole an inch or 

 two in length. Flowers yellowish, with a 5-lobed, glandular disk. Drupes 

 red, acid. May. 



* * ♦ Leaves simple. 



7. R. CotIn'us. Venetian Sumac. — Z>i-5. obovate, entire ; /s. mostly abor- 

 tive; pedicels finally elongated and clothed with long hairs. — A small shrub, tJl 

 liigh, native in Ark. according to Nuttall, remarkable chiefly for the very sin- 

 gular and ornamental appearance of its long, difl'use, feathery fruil-stalks, 

 showing in the distance as if the plant were enveloped in a cloud of smoke. 

 Flowers small, in terminal, compound panicles. Leaves smooth, entire, nuich 

 rounded at the end. In Italy the plant is used for tanning, f 

 18 



