BETULACE^ 193 



extremely tough, dark dull yellow-green above, light yellow-green and furnished 

 with conspicuous tufts of pale hairs in the axils of the veins below, 3'-5' long, l^'-2' 

 wide, with slender midribs impressed and puberulous above, light yellow and pubes- 

 cent below, and numerous slender veins forked near the margins, turning clear 

 yellow before falling in the autumn; their petioles about V long; stipules rounded 

 and often short-pointed at the apex, ciliate on the margins, with long pale hairs, 

 hairy on the back, about ^' long and |' broad. Flo-wers : staminate aments about 

 1' long during their first season, with light red-brown rather loosely imbricated 

 scales narrowed into long slender points, becoming when the flowers open 2' long, 

 with broadly obovate scales rounded and abruptly contracted at the apex into short 

 points, ciliate on the margins, green tinged with red above the middle, light brown 

 toward the base; pistillate aments slender, about \' long, on thin hairy stems, their 

 scales lanceolate, acute, light green, often flushed with red above the middle, hirsute 

 at the apex, decreasing in size from the lowest. Fruit : nuts '^' long, about ^' wide, 

 rather abruptly narrowed below the apex, their involucres in clusters l^'-2' long 

 and f'-l' wide, on slender stems about 1' in length. 



A tree, occasionally o0-60 high, with a short trunk 2 in diameter, usually not 

 more than20-30 tall, with a trunk 18'-20' thick, long slender branches drooping at 

 the ends and forming a round-topped or open head frequently 50 across, and slender, 

 very tough branchlets, light green, coated with pale hairs when they first appear, 

 becoming light orange color and very lustrous at midsummer, dark red-brown and 

 lustrous during their first winter, and then gradually darker brown and losing their 

 lustre. Winter-buds ovate, light chestnut-brown, slightly puberulous, ^' long. 

 Bark about Y thick, broken into thick narrow oblong closely appressed plate-like 

 light brown scales slightly tinged with red on the surface. Wood strong, hard, 

 tough, durable, light brown tinged with red or often nearly white, with thick pale 

 sapwood of 40-50 layers of annual growth; used for fence-posts, handles of tools, 

 mallets, and other small articles. 



Distribution. Dry gravelly slopes and ridges often in the shade of oaks and other 

 large trees; Island of Cape Breton and the shores of the Bay of Chaleur, through 

 the valley of the St. Lawrence River, and along the northern shores of Lake Huron 

 to western Ontario, northern Minnesota, the Black Hills of Dakota, eastern and 

 northern Nebraska, eastern Kansas and southward to northern Florida and eastern 

 Texas; most abundant and of its largest size in southern Arkansas and Texas. 



2. Ostrya Kno"wltoni, Gov. Iron-wood. 



Leaves oval to obovate, acute or rounded at the apex, gradually narrowed and 

 often unequal at the rounded wedge-shaped rarely cordate base, sharply serrate, 

 with small triangular callous teeth, covered with loose pale tomentum when they un- 

 fold, at maturity dark yellow-green and pilose above, pale and soft-pubescent below, 

 l'-2' long, I'-l^' wide, with slender yellow midribs slightly raised on the upper side, 

 few slender primary veins connected by obscure reticulate veinlets, turning dull 

 yellow in the autumn before falling; their petioles ^'|' loiig; stipules pale yellow- 

 green, often tinged with red toward the apex, ^' long, about ^' wide. Flovrers: 

 staminate aments on stout stalks covered with rufous tomentum and sometimes ^' 

 long, rarely sessile, about ^ long during their first season, with dark brown puber- 

 ulous scales gradually contracted into long slender subulate points, becoming when 

 the flowers open I'-l^' long, with broadly ovate concave scales abruptly narrowed 

 into nearly triangular points, yellow-green near the base, bright red above the mid- 



