32 Spring Flora of Ohio. 



Cor'y-Ius ros-tra'-ta Ail. Beaked Hazel-Nut. — Leaves ovate or ovate- 

 oblonj^, somewhat cordate; the invohicre proloiifjed into a narrow 

 tubular beak. 



4. Genus BET'-U-LA. — vSterile catkins sessile, long and drooping, 

 flowers opening with or in advance of the leaves; fertile catkins ob- 

 long or cylindrical, peduncled; outer bark usually separable in sheets. 



A. Trees; leaves sen-ate or obscure/y lohed. 



'b. Bark bro'a'n or yellow gray, more or less s^eeet aroiiiafic. 



Bet'-u-Ia len'-ta L. Sweet. Black. Cherry or Mahogany Birch. Bark 



of trunk close, outer layer scarcely laminate; leaves oblong-ovate, 

 sub-cordate; fruiting catkins oblong-cylindrical, the scales with short 

 divergent lobes. 



Bet'-u-la lu'-te-a :Mx. f. Yellow or Gray Birch. — Bark of trunk yel- 

 lowish gray or silvery gray, detaching in filmy layers; twigs less 

 aromatic than the preceding; leaves ovate-elliptical, ^scarcely or not at 

 all cordate; fruiting catkins oblong-ovoid, the scales with narrow, 

 barely spreading lobes. 



b. Bark reddish or broivn, becoming in young tiees conspicuously very 

 loose and /or)i, and finally i>i old trees rough like that of the Black Cherry.\ 



Bet'-u-la ni'-gra L. River Birch: Red Birch. — Leaves rhombic-ovate, 

 acutish at both ends, irregularly doubly serrate or obscurely, 9-1 (> 

 lobed. 



A. Shrubs, leaves crenate, roundish or cuneate. 



Bet'-u-la pu'-mi-la L. Low Birch. — Stems 2-8 ft. high, not glandu- 

 lar; young branches and }Oung leaves beneath mosth' soft downy; 

 leaves obovate, roundish or orbicular, j4-l '4^ in. long, pale beneath. 



5. Genus AL'-NIIS. — Fertile catkins ovoid or oblong, the scales 

 thick and woody in fruit, persistent; shrubs or small trees. 



Al'-nus in-ca'-na (L.) Willd. Speckled or Hoary Alder. — Leaves 

 broadly oval or ovate, roundish at base, whitened and mostly downy 

 beneath. 



Al'-nus ru-go'-sa (Ehrh.) Koch. (./. serriilata Willd. 1 Smooth 

 Alder. — Leaves obovate, acute at base, green both sides. 



, XIV. Order FA-GA'-CE-yE. OAK FAMILY. — Trees or shrubs; ster- 

 rile flowers in catkins ; fertile flowers in a cupule of indurate bracts. 



