FOKEST TREES. 211 



smooth and whitish. A plant with a slender stem, erect or 

 climbing by rootlets, three to eight feet high. Very much re- 

 sembling the Rhus Toxicodendron of the Atlantic States. Com- 

 mon from Southern California to British Columbia. 



It. venenata, DC. - Poison Sumach, Poison Dogwood, Poison 

 Elder. Branchlets and leaf -stalks smooth ; leaflets seven to 

 thirteen, ovate or oblong, abruptly pointed. Fruit small, 

 globular, dun color, in loose axillary panicles, hanging on late 

 in winter. A rather handsome, upright shrub or tree, some- 

 times twenty feet high. In swamps and low ground. Supposed 

 to be the most poisonous of all the species, but there are many 

 persons who can handle it with impunity. 



K. Toxicodendron, Linn. Poison Ivy, Poison Oak. Leaves 

 composed of three rhombic-ovate leaflets, mostly pointed and 

 rather downy beneath, variously cut-lobed or toothed. Fruit 

 same as the last, but leaves usually yellow after frosts, but 

 sometimes slightly tinged with red. Usually climbing by root- 

 lets, over rocks or ascending trees to a great hight, and the stem 

 becoming as large as a man's arm. A species quite variable in 

 form of growth, but always readily distinguished by its leaves 

 and fruit. Michaux describes a low growing, southern form, 

 under the name of the Oak-leaved (quereifolium), of a more 

 erect habit, with variously lobed leaves, but the leaflets are only 

 three in number. A common plant throughout the Atlantic 

 States and westward to the Rocky Mountains. The following 

 are all innoxious species, and some of them cultivated for or- 

 nament. 



R. ctttomridos, Nutt. American Cotinus. Leaves simple, thin, 

 oval-obtuse, entire, acute at the base, the upper ones long peti- 

 oled. Flowers perfect in an open panicle, the pedicles mostly 

 abortive, elongating, and becoming plumose as in the common 

 Smoke-tree or Venetian sumach tree in gardens. Nuttall says 

 that during his tour into the interior of Arkansas Territory, in 

 1819, he discovered this species on the high, broken calcareous 

 rocky banks of the Grand River, near a place called " Eagle's 

 Nest." A large shrub, but it has recently been reported to have 

 been found growing in Alabama, to the hight of twenty feet or 

 more, with a stem nearly or quite a foot in diameter. Not poi- 

 sonous, neither are any of the following species except the last. 

 R. typhina Linn. Staghora Sumach. Leaflets, eleven to thirty- 

 one, lanceolate-pointed, serrate, smooth, pale beneath. Young 

 branches, leaf stalks, and fruit, densely velvety or hairy. Fruit 



