328 BETULACEJ&. 



Toor soils, in rocky, mountainous woods, common. May. A small and slender , 

 very graceful tree. 20 to 40 feet high, with a chalky-white bark. Leaves tapering 

 to a long point as tremulous as an Aspen, on petioles 1 inch or more long. Aments 

 long pendulous. Poplar-leaved Birch. 



2. B. papyracea, Ait. Paper Birch. Canoe Birch. 



Leaves ovate, acuminate, dcubly-serrate, the veins hairy beneath, small abov 

 lateral lo'm of the fruit-bearing bracts short and rounded. 



Hillside wood?, common. May, June. A tree 40 to 70 feet high, with fine- 

 grained wood, and very tough durable bark, white externally, seperating into pa- 

 per-like laj-ers. Leaves 2 to 3 inches long, % as wide dark-green above, pale 

 glandular-dotted ui " rneath. Sterile aments! to 2 inches long. 



** Trees a . or yellowish bark; leaves with short petioles. 



3. B; I Red Birch. River Birch. 



Leaves rlv „ute at each end, doubly serrate, whitish and downy 



underneain s socio what peduncled, woolly ; bracts with oblong-li ]_'?.! 

 nearly ejcraal lobes. 



Low riv< non. May. A tree 30 to o0 feet high, with reddish -brown, 



bark, whi -. ,-ccrae? very loose and torn, hanging in shreds. Leaves 3 



inches long on petioles x / 2 to % inch long, dark-green above. 



4. B LENTA, L. Black Birch. Sweet Birch. 



Leaves cordate-ovati . pointed, sharply and finely doubly serrate; hairy on the 

 veins ten. i#nt$ elliptical, thick, erect, somewhat hairy. 



Moist ric". unon. April, May. A. beautiful tree 40 to 60 feet high, 



with adiametei of 1 to 3 feet, covered with a chestnut-brown dark. Branches 

 ^lender, spotted with white. Leaves 3 to 4 inches long, about % as wide. The 

 wood has a clo-e grain and is susceptible of a fine polish, valuable for cabinet work. 

 The bark and yoang twigs are spicy-aromatic. 



***Shriirbs with brotvnish bark and rounded crenaie-toothed leaves. 



5. B. pumila, L. Low Birch. Dwarf Birch. 



Erect or ascending; leaves obovate or roundish-elliptical, coarsely crenate-toothed, 

 ihe younger downy and nearly orbicular; fertile catkins cylindrical; scales more 

 or. less unequal 3-lobed; fruit broadly winged. 



Mountain bogs, rare. JPursh. May, June. A shrub 2 to 5 feet high, with smooth 

 or sometimes warty branchlets. the young twigs downy. Leaves on short petiole*; 

 1 to 1% inch long, pale or whitish underneath. 



2. ALNUS, Tourn. Alder. 



The ancient Latin name. 



Monoecious. Sterile aments long and droopiDg, cylin- 

 dric, with 5 bractlets and 1 to 3 flowers under each scale ; 

 each flower with a 4-parted calyx and 4 stamens with very 

 short filaments. Fertile aments ovoid or oblong, the 

 fleshy scales each 2 -flowered, with a calyx of 4 small scales 

 coherent with the scales or bracts of the anient, which be- 

 come thick and woody in fruit, all coherent below and per- 

 sistent. — JShru-bs or small trees, arising from large and strong 

 roots, stalked leaf buds furnished with a single scale, alternate simple 

 haves, and the aments produced at the close of summer, and expand- 

 ing in early spring. 



