K.EY, BASED UPON LEAVES. 



A KEY, BASED UPON THE LEAVES, 



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

 out of Season for procuring the flowers. 



N. B. In this Key no pretension is made to exclude species not of this series, and hence it 

 is necessary in all cases to confirm identification, by a careful comparison with the more 

 extensive description given of the species in its proper place. 



ci. Deciduous Leaves falling in autumn. 

 b. Simple Leaves. 



C. Laminate with well marked blade and petiole. 

 cl. Main rib single pinnately veined. 

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



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



jT 2 . Small, 2-5 in. long, of thicker and firmer texture. 



9. NYSSA MULTIFLORA. 

 e 2 . Serrate, serulate or dentate. 

 f. Inequilateral and cordate or truncate at base. 



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



3. TILIA AMERICANA. 

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



12. CELTIS OCCIDENTALS. 

 gr 3 . Ovate, oblong and 



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



7t 2 . Smoothish and 



Flowers and fruit in fascicles 33. ULMUS AMERICANA. 



Flowers and fruit in racemes .34. ULMUS RACEMOSA. 



/ 2 . Equilateral and obtuse, rounded or cordate at base. 

 ff. Veins straight; leaves thinish. 

 /*. 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 VlRGIKIACA. 



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 BALSAMIFERA. 



