Proccedino^s of the Ohio State Academy of Science 173 



Styracaceae. Storax Family. 

 68. Mohrodendron Britt. Silverbell. 



Small trees or shrubs, more or less stellate-pubescent, with 

 large, white, bell-shaped flowers and 2-4-winged, dry fruit. 



I. Mohrodendron carolinum ( L. ) Britt. Silverbell. A 

 small tree with diaphragmed pith. In woods and along streams. 

 Va. to 111., Fla., and Ala. 



Subclass, Sympetalae Hypogynae. 



Order, Gentianales. 



Oleaceae. Olive Family. 



69. Fraxinus L. Ash. 



Trees with opposite leaves, in our species odd-pinnate. Fruit 

 a samara. 



1. Lateral leaflets sessile, 7-11; samara winged all around; calyx none. 

 F. nigra. 



1 . Lateral leaflets more or less stalked ; calyx present in the carpellate 



flower. 2. 



2. Body of the samara terete or nearly so. the wing chiefly terminal; 



twigs not 4-sided. 3. 



2. Body of the samara flat, the wing extending around it; twigs 4-sided, 



often with 4 sharp ridges especially on vigorous shoots ; leaflets 

 7-11. F. guadrangulata. 



3. Wing almost entirely terminal. 4. 



3. Wing extending somewhat down the sides of the body of the samara; 



leaflets 5-9. 5. 



4. Leaves and twigs glabrous or nearly so, pale below^ leaflets 5-9. F. 



anici'icaiia. 



4. Leaves and twigs pubescent, leaflets 7-9. F. biltmoreana. 



5. Wing of the samara spatulate. 6. 



5. Wing long linear. F. darlingtonii. 



6. Leaves, twigs, and pedicels glabrous or nearly so; leaves bright green 



on both sides. F. lanceolata. 

 6. Leaves, young twigs and pedicels velvety-pubescent; samara 1-2 in. 

 long. F. pennsylvanica. 



I. Fraxinus americana L. White Ash. A large tree of 

 rapid growth, with glabrous twigs. Leaflets 5-9, ovate, ovate- 

 lanceolate, oblong, or rarely slighth' obovate, entire or denticulate, 



