146 



TKEES OP THE NOKTHEKN UNITED STATES 



3. B6tula alba, L. (EUROPEAN WHITE BIRCH.) 

 Leaves ovate, acute, somewhat deltoid, unequally 

 serrate, often deeply cut, nearly smooth ; in var. 

 pubescens covered with white hairs. Fruit brown, 

 cylindric, drooping. A tree, 30 to 60 ft. high, 

 with a chalky-white bark ; from Europe, exten- 

 sively cultivated in this country, under many 

 names, which indicate the character of growth or 

 foliage ; among them may be mentioned pendula (weeping), laciniata 

 (cut-leaved), fastigiata (pyramidal), atropurpurea (purple-leaved), 

 and pubescens (hairy-leaved). 



4. B6tula 16nta, L. (SWEET, BLACK or 

 CHERRY BIRCH.) Leaves and bark very 

 sweet, aromatic. Leaves ovate or ovate- 

 oblong, with more or less heart-shaped base, 

 very acute apex, and doubly and finely ser- 

 rate margin, bright shining green above, 

 smooth beneath, except the veins, which are 

 hairy. Fruit 1 to li^ in. long, cylindric, 

 with spreading lobes to the scales. A rather 

 large tree, 50 to 70 ft. high, with bark of 

 trunk and twigs in appearance much like 

 that of the garden Cherry, and not splitting 

 into as thin layers as most of the Birches. Wood rose-colored, fine- 

 grained. Moist woods, rather common throughout ; also cultivated. 



5. B6tula lutea, Michx. f . (YELLOW 

 OR GRAY BIRCH.) A species so like the 

 preceding (Betula lenta) as to be best 

 described by stating the differences. 

 Leaves and bark are much less aro- 

 matic. Leaves 3 to 5 in. long, not so 

 often nor so plainly heart-shaped at 

 base, usually narrowed ; less bright 

 green above, and more downy beneath ; 

 more coarsely serrate. Fruit not so 

 long, and more ovate, with much larger 

 and thinner scales, the lobes hardly 

 spreading. A large tree, 50 to 90 ft. 

 B. lutea. high, with yellowish or silvery-gray 



bark peeling off into very thin, filmy layers from the trunk. Wood 

 whiter, and not so useful. Rich, moist woodlands, especially north- 

 ward ; also cultivated. 



