252 



BETULACEiE. 



[Diclinous Exogens. 



the quantity of sugar it contains, ferments, and is converted into an agreeable sparkling 

 wine, much valued in the North of Europe ; it has been found to contain free acetic acid 

 and some saline matters ; Birch wine has a popular reputation as a remedy for stone 

 and gravel. Betula nigra and lenta furnish the North Americans with sugar of as good 

 quality as that extracted from the Sugar Maple. The bark of the Common Alder is 

 bitter and astringent, and has been employed for gargles, and with success in cases of 

 ague. The leaves and female catkins are employed by dyers and tanners in some 

 countries. 



GENERA. 



Betula, L. 



Pteroearyon, Spach. 



Apterocaryon, Spacl). 



Betulatter, Spach. 

 Alnus, L. 



Alnaster, Spach. 



Cletkropsis, Spach. 



Numbers. Gen. 2. Sp. 65. 



Position. — Myricaceae. — BetulacejE. — Altingiacese. 



Pinacew. 



