66 KEY FOR THE IDENTIFICATION OF TREES AND SHRUBS 



105. Leaf once compound: one series of leaflets. . 106 

 105. Leaf twice compound: some of the leaflets 



cut to the midrib to form a secondary series 



of leaflets 115 



106. Leaf trifoliate: one pair of leaflets 



plus a terminal leaflet 107 



106. Leaf lets more than three 109 



107. Margin of leaflets entire. 



Golden Chain Tree 

 Laburnum alpinum 

 Bercht. & Prsl. 

 107. Margin of leaflets Irregularly toothed, 

 plant smooth, poisonous to the touch. 

 See #112. 



Poison Ivy 



Rhus Toxicodendron L. 

 107. Margin of leaflets irregularly 

 and coarsely toothed, stems and 

 petioles armed with prickles, leaf- 

 lets sometimes 5. 



Genus Rubus 108 



A large and variable genus, contain- 

 ing many hybrids. The following are 

 among the common species. 

 108. Canes arched-recurving, prickles 

 stout, leaflets smooth above, 

 velvety beneath, occasionally 5 

 leaflets on leaves of older stems. 

 Blackberry 



Rubus frondosus Bigel. 

 108. Leaflets rhombic -ovate, doubly 

 serrate, smooth, dull, stems 

 elongate, becoming prostrate, 

 prickles stout, backward turn- 

 ing . . . .Dewberry 



Rubus vi I losus Ait. 

 108. Leaf lets smooth, firm, shining, 

 dark green, stems prostrate 

 trailers, prickles backward 

 turning . . Small Dewberry 



Rubus hispldus L. 



109. Leaflets 5, palmate 110 



109. Leaflets 5 or more, odd-pinnate, 



See #108 Ill 



