KEY, BASED UPON LEAVES. 



A KEY, BASED UPON THE LEAVES, 



Designed as an Aid in Identifying the Species represented in Parts I, II and III 

 when out of Season for procuring the flowers. 



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

 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. 

 6. Simple Leaves. 



c. Laminate with well-marked blade and petiole. 

 l t Main rib single pinnately veined. 



. Entire or nearly so, pointed at both ends and 



/. Opposite, 3-5 in. long, of rather thick texture. .9. NYSSA MULTIFLORA. 

 /" 2 . Alternate and 



Large, 5-10 in. long, thinnish 1. MAGNOLIA ACUMINATA. 



Smaller, 8-6 in. long, thick, whitish and 

 Glaucous beneath, lanceolate to oval. . . .51. MAGNOLIA GLAUCA. 



Pubescent on veins beneath 61. DIOSPYROS VIRGINIANA. 



6 2 . Serrate, serulate or dentate. 

 /. Inequilateral and cordate or truncate at base. 



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



3. TILIA AMERICANA. 

 </ 2 . Ovate, long- taper-pointed from a broad base. 



12. CELTIS OCCIDENTALS. 

 </ 3 . Ovate-oblong and 



h. Very rough, especially above, rugose 11. ULMUS FULVA. 



7i 2 . Smoothish and 



Flowers and fruit in fascicles. 33. ULMUS AMERICANA. 



Flowers and fruit in racemes 34. ULMUS RACEMOSA. 



f' 2 . Equilateral and obtuse, rounded or cordate at base. 

 (j. 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 VlRGINICA. 



Unequally and sharply serrate, nutlet subtended by a leafy 



bract 42. CARPINUS CAROLINIANA. 



h?. Ovate and 



i. Finely and closely serrate, smooth, whitish and reticulate-veined 



beneath 47. POPULUS BALSAMTFERA. 



i 2 . Doubly serrate and 

 j. Thinnish; petioles downy and of aromatic flavor. 



Bark of trunk yellowish-gray 17. BETULA LUTEA. 



Bark reddish-brown. . .44. BETULA LENTA. 



y 2 . Veins incurved. 



h. Orbicular heart-shaped, 4-6 in. long 63. MORUS RUBRA. 



7i 2 . Orbicular-ovate; petioles laterally compressed, 



Coarsely dentate . . . . 18. POPULUS GRANDIDENTATA. 



Serrate 72. POPULUS TREMULOIDES. 



