TEHON: FIELDBOOK OF NATIVE ILLINOIS SHRUBS 19 



X. Leaves not cordate, or if so each with 

 only 1 main nerve. 

 Y, Petioles concealing buds in their hol- 

 low bases Dirca, p. 206 



Y. Petiole bases solid and buds axillary. 

 Z. Leaves with marginal veins ending 



in the tips Cornus, p. 212 



Z. Leaves without such lateral veins. 

 a. Buds covered by 1 scale only . . . 



Salix, p. 34 



a. Buds with 2 to several scales. 

 b. Leaves resinous-dotted beneath 



Gaylussacia, p. 228 



b. Leaves not resinously dotted. 

 c. Leaf blades mucronate- 



tipped Nemopanthus, p. 165 



c. Blades not mucronate. 



d. Blades thick and revolute, 

 leaves and branches scurfy 

 with scales 



Chamaedaphne, p. 224 



d. Blades thin, not revolute, 

 no scurfy scales present 

 Vaccinium, p. 229 



Q. Leaf margins either lobed or toothed, often both, 

 e. Leaves definitely lobed, often toothed also. 



f. Leaves linear; margins cut to the midrib to form 



20 or more half-wedge-shaped lobes 



Comptonia, p. 59 



f. Leaves not linear. 



g. Vines with palmately veined leaves. 



h. Tendrils opposite at least some of the 

 leaves; margins serrate. . 

 i. Petioles uniformly glabrous or pubescent 



Vitis, p. 185 



i. Upper half of petiole pubescent, lower 



half glabrous Ampelopsis, p. 194 



h. No tendrils present; margins without teeth, 

 j. Leaves densely pubescent beneath, fruit 



red Cocculus, p. 77 



j. Leaves glabrous except on the veins be- 

 neath. 



k. Leaves peltate, fruit blue '. 



Menispermum, p. 78 



k. Leaves deeply cordate, fruit black 



Calycocarpum, p. 80 



g. Erect shrubs. 



1. Leaves palmately lobed and veined. 



m. Armed with spines or prickles 



Grossularia, p. 94 



m. Unarmed. 



