78 



BETULACEAE. THE BIRCH FAMILY. 



Trees or shrubs with simple, petioled, alternate (in pairs on the 

 older branches of Betula) leaves; staminate flowers in long drooping 

 catkins, 1-3 in the axil of each bract, the pistillate in short lateral 

 or terminal aments; fruit a nut or samara. 



Staminate flowers solitary in the axil of each bract, without a 



calyx, pistillate flowers with a calyx; nut wingless. 

 Bark of tree smooth; staminate aments in winter enclosed in 

 bud scales; nut exposed, its subtending bract more or 



less irregularly 3-cleft 1 Carpinus. 



Bark of older trees shreddy; staminate aments in winter 



naked; nut enclosed in a bladder-like bract 2 Ostrya. 



Staminate flowers 3-6 in the axil of each bract, with a calyx, 



pistillate flowers without a calyx; nut winged. 

 Winter buds sessile; stamens 2; fruit membranous and hop- 

 like; fruiting bract deciduous at the end of the season 



when the nut escapes ; . . . . . .' ,3 Betula 



Winter buds stalked; stamens 4; fruit woody and cone-like; 



fruiting bracts woody and persisting after the nuts escape, 4 Alnus. 



1. CARPINUS. THE HORNBEAM. 



Carpinus caroliniana Walter. WATER BEECH. BLUE BEECH. 

 Plate 30. A small tree up to 3 dm. in diameter, usually 1-1.5 dm. in 

 diameter with fluted or ridged trunks; bark smooth, close, gray; twigs 

 hairy at first, soon becoming glabrous; leaves ovate-oblong, average 

 leaves 6-10 cm. long, pointed at the apex, double-serrate, hairy when 

 young, glabrous at maturity except on the veins and in the axils beneath, 

 pubescent, not glandular, staminate catkins appearing in early spring; 

 nut at the base of a 3-cleft bract about 2 cm. long, nut broadly ovate, 

 compressed, pointed and about 5 mm. long; wood heavy, hard, tough 

 and strong. 



Distribution. Nova Scotia west to Minnesota and south to Florida 

 and Texas. In Indiana it is frequent to common throughout the State 

 in moist rich woods. It prefers a moist rich soil; however, it has a range 

 from the tamarack bog to the dry black and white oak slope. It is 

 tolerant of shade and is seldom found outside of the forest. 



Remarks. This tree is too small and crooked to be of economic im- 

 portance. It is regarded as a weed tree in the woodland, and should be 

 removed to give place to more valuable species. 



