34 TREES OF THE NORTHERN UNITED STATES 



the midrib, bringing the two halves together. Peach. 

 Plicate : folded several times length wise,like a fan. Birch. 

 Convolute: rolled edgewise from one edge to the other. 

 Plum. Involute : both edges rolled in toward the midrib 

 on the upper side. Apple. Revolute : both edges rolled 

 backward. Willow. Obvolute : folded together, but the 

 opposite leaves half inclosing each other. Dogwood 



