100 Proceedings of the Ohio State Academy of Science 



bark very bitter ; some axils with 2 or 3 hairy buds of 

 nearly equal size; trees. Amygdalus. (43). 



68. Twigs not green or red and green unless the plants are 



low shrubs, but gray, brown, black, or reddish. 69. 



69. Bundle scars 5 or more in the broad U-shaped leaf scar; 



tips of the buds quite downy; small trees. 



Sorbus. (36). 



69. Bundle scars 3. 70. 



70. Buds rounded at the apex, often clustered at the tip of 



the twig; twigs glandular dotted. Myrica. (13). 

 70. Buds rounded at the apex ; scales thick ; twigs often 

 zigzag; plant usually with some thorns, not glandular 

 dotted. Crataegus. (41). 



70. Buds pointed ; plants sometimes with thorn-like stunted 



branches, not glandular dotted. 71. 



71. Buds glabrous or slightly pubescent; twigs usually 



glabrous and slender, some shade of black, brown, or 



reddish, often with 2 or 3 axillary buds; some with 



self-pruning scars. Prunus. (42). 

 71. Buds downy or strongly pubescent, conical, pungent; 



twigs glabrous, mostly yellow-olive ; trees with erect 



growth, the branches not spreading as in most of the 



apples. Pyrus. (37). 

 71. Buds downy or strongly pubescent; twigs strongly 



pubescent or if glabrous then dark reddish-brown ; 



trees with rounded or spreading crowns. 



Malus. (38). 



71. Buds and twigs very pubescent; terminal bud with long 



spreading scales ; shrubs or small trees with globose 

 berry-like drupes containing 2-4 stones. 



Rhamnus. (60). 

 —72— 



72. Bundle scars i, or several closely united in a curved 



line, appearing as i. 74. 

 72. Bundle scars more than i but not in an ellipse or ring. 78. 

 72. Bundle scars numerous, in an ellipse or ring; buds small 



and fiat or superposed. 73. 



