A KEY BASED UPON THE LEAVES. 



Designed as an Aid in identifying the Species represented in Farts I to X 

 inclusive, when out of Season for procuring the Flowers. 



N. B. As this key applies only to the species thus far represented in AMERI- 

 CAN WOODS it is important always to confirm identification by applying the 

 more detailed description given in its proper place. 



a. Deciduous Leaves. falling in autumn. 

 b. Simple Leaves. 



c. Laminate with well marked blade and petiole. 

 d. Main rib single pinnately veined. 

 e. Entire or nearly so, pointed at both ends and 

 /. Opposite 



3-5 in. long, thick, lustrous above 9. NYSSA MULTIFLORA. 



5-6 in. long, thin, dull above 89. CATALPA BIGNONIOIDES. 



/*. Alternate, thinnish and in length 

 g. 6-12 in. 



Oblong, petioles in 1. MAGNOLIA ACUMINATA. 



Lance-obovate; petioles, scarcely 2 in. long 76. ASINIMA TRILOBA. 



g\ 2-7 in., 



h. Thickish, and with light-colored pubescence, at least on the veins 

 beneath. 



Petioles about 1 in. long 61. DIOSPYROS VIRGINIANA. 



Petioles about 4 inch long 110. NYSSA OGECHE. 



W. Thinnish, oblong-obovate (often remotely serrate). 



Convolute in the bud 193. SALIX NUTTALLII. 



Involute in the bud 238. SALIX SITCHENSIS. 



r. 1-3 in., distinctly bluish-green 214. QUERCUS DOUGLASII. 

 j . Alternate, opposite and scattered upon the same plant, linear. 



134. CHILOPSIS SALIGNA. 

 e 2 . Serrate, serulate or dentate. 

 /. Inequilateral and cordate or truncate at base, 

 g. Ovate-orbicular, large, 4-5 in. or more in length. 



3. TlLIA AMERICANA. 



fir 5 . Ovate, long-taper-pointed from a broad base. 



12. CELTIS OCCIDENT ALIS. 

 g*. Ovate-oblong and 



/*. Very rough, especially above, rugose 11. ULMUS FULVA. 



ft 2 . Smoothish and 

 i. 2-4 in. long, flowers and fruit in 



Fascicles 33. ULMUS AMERICANA. 



Racemes 34. ULMUS RACEMOSA. 



i 5 . 1-2 in. long and only slightly inequilateral. 



114. PLANERA AQUATICA. 



/*. Equilateral and obtuse, rounded or cordated at base. 

 g. Veins straight or nearly so, leaves thinnish. 

 h. Ovate-oblong. 



Coarsely serrate with remote teeth, one at the end of each vein, 

 ciliate and covered with silky white hairs. 



16. FAGUS FERRUGINEA. 

 Doubly and sharply serrate, nutlet inclosed in a papery sac. 



41. OSTRYA VIRGINICA. 



Unequally and sharply serrate, nutlet subtended by a leafy bract. 



42. CARPINUS CAROLINIANA, 



