BETULA 



251 



above when mature, paler and glabrous or somewhat tomentose beneath, 

 3.5-8 cm. long, 2.5-6 cm. wide, petioles 8-15 mm. long; staminate catkins 

 2-3 together, 6-10 cm. long, pistillate catkins oblong-cylindric, 1-1.5 cm. 

 long, about 4 mm. in diameter; fruiting catkins spreading, pedicelled, 



TjeTula 



Ih.lutea 



