1 30 MAINE AGRICULTURAL EXPERIMENT STATION. I9OI. 



A. Cultivated chiefly for fruit. 

 B. Color of fruit reel. 



C. Stems slender, trailing; leaves evergreen. 



D. Apex of leaves :icute Oxycoccus 



DD. Apex of leaves obtuse or refuse. 



macrocarpon 

 CC. Stems stouter though creeping ; branches erect, 



tufted Vitis-Idaea 



CCC. Stems erect, much taller (2-10 feet). 



D. Leaves small (%-% inch long). 



parvijolium 

 BB. Color of fruit blue or black. 



C. Plant low, %-% feet high. 



D. Foliage evergreen. 



E. Leaves small (K—J^ inch long) . 



nitidum 

 EE. Leaves larger (54-1 inch long). 



Myrsinites 

 DD. Foliage deciduous. 



E. Surface of leaves glabrous. 



F. Leaves pale beneath, not 

 shining above . . . , vaculans 

 wax. pallidum of corymbosum 

 FF. Leaves not paler beneath (ex- 

 cept sometimes in Pennsyl- 

 vanicum) ; shining, at least 

 above. 

 G. Flowers solitary in the 

 axils. 

 H. Branches sharply 

 angled. 



Myrtillus 

 HH. Branches not 

 angled. 



cwspitosum 



GG. Flowers in fascicles or 



short racemes. 



H. Fruit blue, glaucous 



Pennsylvan icum 



HH. Fruit black. 



nigrum 



