1 6 KEY TO GENERA AND SPECIES 



21. Leaf length more than twice the width. Juice 

 not milky. Southern New England south- 

 ward and westward. (Figs. 

 26, 27.) Hackberry, Sugar- 

 berry, Nettle-tree, Oneberry, 

 Celtis occidentalis L. 



22. Fruit globular, about f of an 

 inch thick. Cult, and es- 

 caped. Native in eastern p . g ^ Hackb " erry . 

 Asia. (Fig. 28.) Paper Mul- 

 berry, Broussonetia papyri/era (L.) Vent. 



22. Fruit longer than broad, less than \ inch thick 

 Mulberry, 148. 



Fig. 27. Hackberry. 



23. Margins either wavy, toothed, incised, or 

 lobed. (See Figs. 46, 126, 169, 225.) 35. 



23. Margins entire, without any of the above char- 



acters. (See Figs. 40, 150.) 24. 



24. Twigs and bark emitting a pleasant spicy odor 



when bruised. Some of the leaves with a 



