IN THEIR WINTER CONDITION. 11 



scars, t lie raised borders of which form at the lower angles small protub- 

 erances; bundle-scars in three areas; terminal buds none; lateral buds 

 two or three superposed, contiguous (or single), low. densely pubescent. 

 Rare, on dry bills. 



1". ACER, Tourn. Inst. 1700; L. Spec. 17-"):;. 



A. sacciiarinum, L. Spec. 17,53. Soft Maple. 



A large tree, with reddish or yellowish-brown, glabrous twigs, V- 

 shaped, opposite leaf-scars not cpiite meeting, but joined by a line, and 

 three bundle-scars. Terminal buds with two or three pairs, the appressed 

 lateral with one or two pairs of smooth, ovate, obtuse scales. Common 

 along the 13. ue, and the Kansas river below the mouth of the Blue. 



A. Negundo, L. Spec. 1753. Box Elder. 



A small or medium tree with yellow-green or dark red-brown, glab- 

 rous and glaucous twigs, above the nodes of which is an impression, 

 marking the position of the bases of the petiole during the previous sea- 

 son. The leaf-scars are narrow, V-shaped, opposite, the lateral angles 

 meeting and extending upwards into a free appendage Bundle-scars are 

 three, or the lateral double. Buds pubescent, gray, the scales about two 

 pairs, ovate, obtuse. Frequent in lowland woods. 



16 STAPIIYLEA, L. Gen. 1737; Spec. 1753. 



S. trifolia, L. Spec. 1753. Bladder-nut. 



A shrub with brownish gray or mottled yellow, glabrous twigs, white- 

 streaked branches and trunks, semicircular or crescent, opposite leaf- 

 scars, with about three bundle-scars, and stipnle-scars at the angles but 

 not meeting. Terminal bud absent; lateral buds with two pairs of glab- 

 rous scales. Infrequent along bluffs. 



17 RHUS. L. Gen. 1737; Spec. 17.-);;. 



Twigs glabrous R. glabra . 



Twigs pubescent. 



Buds hidden by leaf-scar II. Canadensis. 



Buds not hidden R. radicans. 



R. GLABRA, L. Spec. 1753. Smooth Sumac. 



A shrub with large yellow-brown pith, large, reddish, glabrous and 

 glaucous twigs, compressed toward the apex by ridges decurrent from 

 the leaf-scars, which are five-ranked, narrow, horse-shoe shaped and 

 nearly surrounding the bud. Bundle-scars numerous. Terminal buds 

 none; lateral low, naked and densely brown-woolly. Common on dry 

 hills, thickets, etc. 



R. radicans, L. Spec. 1753. Poison Ivy. Poison Oak. 



An erect shrub or a vine climbing by aerial rootlets. Pith white; 

 twigs light brown, striate, minutely pubescent; leaf-scars two-ranked, 

 heart, crescent or Y-shaped, with raised border; bundle-scars five or six: 





