558 IOWA ACADEMY OF SCIENCE 



ABIES GRANDIS Lindl. White Fir. 



Leaves flat, edges tending down, 1% to 2*4 inches long. 



Resin ducts small, lateral, touching epidermis on ventral side, 

 lined with 2 layers of cells. 



Vascular bundles surrounded by a sheath of large, round, loosely 

 joined cells. The large irregular cells separating the bundles 

 and those below lignified. 



Hypodermal cells present within epidermal layer between bands 

 of stomata on lower side, at the edges of the leaf, and scat- 

 tered in groups of 1 or 2 along upper surface. Epidermal 

 cell walls not lignified. 



Stomata present on lower surface of leaf, 7 to 10 rows each side 

 of midrib. 



Material from Jamaica Plains, Massachusetts. 



Plate LVII. 



Figure 1. — Section of leaf of Abies grandis. 



Figure 2. — Section through epidermis and stomata of leaf of 

 A. grandis. 



Figure 3. — Section through resin duct of leaf of A. grandis. 



Figure 4. — Section through vascular cylinder of leaf of A. 

 grandis. 



