22 



3a. Shrubs, with leaves 4 cm. long or less 4. 



3b. Shrubs or trees, with leaves 5 cm. long or more 5. 



4a. Twigs glandular-warty Dwarf Birch, Betula glandulosa. 

 4b. Twigs not glandular Swamp Birch, Betula pumila. 



5a. Twigs and bark with the odor of wintergreen 



Sweet Birch, Betula lenta. 



5b. Twigs and bark without odor of wintergreen 6. 



6a. Fruit clusters woody, persistent on the plant for a long 



time 7. 

 6b. Fruit clusters herbaceous, dropping in late autumn 9. 



7a. Leaves rusty or whitish beneath, and pubescent at least on the 

 veins Speckled Alder, Alnus incana. 



7b. Leaves green beneath, and either pubescent or smooth 8. 



8a. Leaves broadest at or below the middle 



Mountain Alder, Alnus crispa. 

 8b. Leaves broadest above the middle 



Smooth Alder, Alnus ruerosa. 



9a. Tree; fruit a cluster of bladder-like sacs each containing a small 

 achene Ironwood, Ostrya yirgliiiana. 



9b. Shrubs; fruit a nut within a close-fitting involucre 10. 



lOa. Involucre of 2 broad bracts, almost separate and not much 

 longer than the fruit Hazel, Corylus americana. 



lOb. Involucre of united bracts, prolonged into a bristly beak 

 beyond the fruit Beaked Hazel, Corylus ro strata. 



FAGACEAE, the Beech Family 



Trees (or 1 species shrubby), with alternate -simple leaves and 

 monoecious flowers, the staminate flowers in catkins, and the pistil- 

 late solitary or in small clusters. Fruit a nut (or acorn) enclosed 

 in a cup or bur. 



la. Leaves serrate with numerous sharp-pointed teeth 2. 



Ib. Leaves serrate, lobed, or entire, but n6ver serrate with sharp- 

 pointed, teeth; fruit an acorn; pith 5-angled in the young 

 twigs (Oak) 3. 



2a. Bark gray, smooth; buds 3 4 times longer than wide; nut 

 triangular Beech, Fagns grandifolia. 



2b. Bark rough; buds relatively thicker; nut rounded 



Chestnut, Castanea dentata. 



3a. Leaves entire, except for a bristle at the tip 



Shingle Oak, Quercus imbricaria. 



3b. Leaves toothed or lobed, the points bristle-tipped 4. 

 3c. Leaves toothed or lobed, the points without bristles 10. 



4a. Leaves entire below the middle, with a few shallow lobes be- 

 yond Black Jack Oak, Quercus marilandica-.- 



4b. Leaves deeply lobed throughout 5. 



