i 2 KEY TO GENERA AND SPECIES 



15. With one leaf at a node 

 (i. e., leaves alter- 

 nate) 18. 



15. With two or more 



leaves at a node 

 (i.e., leaves opposite 

 or whorled) 16. 



16. Leaf margins strongly 



indented in 2 or 4 

 places, these inden- 

 tations variable, but 

 usually reaching at 

 least i of the dis- 

 tance to the base of 

 the blade. Fruit 

 with a flat wing 

 Maple, 1 86. 



16. Leaves usually with 



only one indentation and this at the base 

 (i. e., leaves heart-shaped), occasionally some 

 leaves with one or two angles or shallow 

 indentations on the sides. No small mar- 

 ginal teeth 17. 



17. Fruit 12 to 1 8 inches long, cylindric Catalpa, 



208. 

 17. Fruit globular or topshaped. Cult. Native in 



Fig. 18. Paulownia. Half of 

 a leaf. 



